Davies SPI REVIEW
After a short walking exercise, the venous pressure at the ankle of a standing normal subject: A: Is greater than the standing ankle pressure at rest B: Is lower than the standing ankle pressure at rest C: Is the same as standing ankle pressure at rest D: Is not affected by chronic venous insufficiency E: Is not affected by deep venous thrombosis
B: Is lower than the standing ankle pressure at rest
When an electrical signal is applied to a piezoelectric element, what happens to the element? A: It undergoes temperature fluctuations B: It expands and contracts C: It produces an electrical signal of the opposite polarity D: It emits electromagnetic radiation E: It loses its piezoelectric properties
B: It expands and contracts
Which of the following statements most correctly describes the occurrence of diastolic flow reversal in the arterial system? A: It is always an abnormal finding B: It is seen in and proximal to high-resistance vessels C: It is most commonly observed in vessels which supply low-resistance beds D: It can be enhanced by body heating E: It is found in the internal carotid artery
B: It is seen in and proximal to high-resistance vessels
When the sound beam is refracted during a sonographic examination which of the following might you detect on the ultrasound image? A: Axial misregistration B: Lateral misregistration C: Reverberations posterior to a reflector D: Enhancement of a reflector E: Electrical interference
B: Lateral misregistration
When increasing the number of transmit focal zones to improve spatial resolution, the trade off is: A: Lateral resolution vs. axial resolution B: Lateral resolution vs. temporal resolution C: Spatial resolution vs. contrast resolution D: Contrast resolution vs. frame rate E: Elevational resolution vs. frame rate
B: Lateral resolution vs. temporal resolution
The term for a transducer that has an array of rectangular elements arranged in a straight line is: A: Annular array B: Linear array C: Curved array D: Oscillating mechanical transducer E: Convex sequenced array
B: Linear array
What type of transducer produced this image? See image for question #199 A: Curved linear array B: Linear array C: Sector D: Phased array E: Tightly curved array
B: Linear array
Which transducer type is best suited to vascular imaging? A: Mechanical sector B: Linear array C: Phased array D: Convex array E: Annular array
B: Linear array
Which condition is most likely in patients having a normal arterial waveform shape, but low velocities across all vessels? A: Hypertension B: Low cardiac output C: Low hematocrit D: Will be unrelated E: Hypotension
B: Low cardiac output
When measuring penetration on a tissue-mimicking phantom, how should the master gain and acoustic output be adjusted? A: Minimum gain, maximum acoustic output B: Maximum gain, maximum acoustic output C: Maximum gain, minimum acoustic output D: Minimum gain, minimum acoustic output E: It doesn't matter how the gain and acoustic output are set when measuring penetration
B: Maximum gain, maximum acoustic output
Volume flow is determined by multiplying the cross sectional area of the vessel with: A: Volume flow rate B: Mean velocity C: Peak velocity D: Minimum velocity E: Velocity range
B: Mean velocity
The layer of the vessel wall that contains smooth muscle fibers is: A: Adventitia B: Media C: Intima D: Internal elastic Lamina E: External elastic Lamina
B: Media
Which prefix equals 10-3? A: Micro B: Milli C: Mega D: Centi E: None of the above
B: Milli
What is the optimal thickness for the matching layer? A: Equal to the thickness of the crystal B: One-fourth of a wavelength C: One-half of the pulse length D: Twice the transducer diameter E: One-half the width of the backing material
B: One-fourth of a wavelength
What sonographic application has the lowest FDA-approved SPTA values? A: Cardiac B: Opthalmic C: Peripheral vascular D: Fetal imaging E: Abdominal
B: Opthalmic
The terms ensemble length and dwell time are synonymous with: A: Persistence B: Packet size C: Pulse repetition frequency D: Color threshold E: Autocorrelation
B: Packet size
Which of the following artifacts commonly results in echoes filling in the lumen of small vessels? A: Refraction B: Partial volume C: Mirror image D: Range ambiguity E: Multipath
B: Partial volume
What type of probe was used to take this image? See image for question #246 A: Curved array B: Phased array C: Linear array D: Mechanical sector E: Tightly curved array
B: Phased array
When you adjust the TGC, what component of the ultrasound system implements the changes? A: Pulser B: Receiver C: Monitor D: Scan converter E: Clock
B: Receiver
While performing a sonographic exam, you increase both imaging depth and scan line density. These adjustments produce the following result: A: Reduced contrast resolution B: Reduced temporal resolution C: Improved axial resolution D: Reduced lateral resolution E: All of the above
B: Reduced temporal resolution
In this image, the Doppler frequency shift exhibits: See images for question #529 A: Aliasing B: Spectral broadening C: Narrow bandwidth D: Mirroring E: All of the above
B: Spectral broadening
The speed of sound is defined as the: A: Speed of the vibrating particles in the medium B: Speed at which the sound wave propagates through the medium C: Number of cycles per second of the vibrating particles D: Inverse of the frequency E: Speed of the electrical impulse applied to the piezoelectric element
B: Speed at which the sound wave propagates through the medium
What are the two equations for divergence angle?
- Sin divergence angle = 1.85/Diameter(mm) x frequency(MHz) - Sin divergence angle = 1.2 x wavelength/ Diameter
What are the 2 equations for focal depth?
- focal depth (cm) = diameter (mm)2 x frequency (MHz)/61.6 - focal depth (cm) = diameter (mm)2/40 x wavelength (mm)
In clinical imaging pressure amplitude ranges from _____ to ______.
-1 million pascals -3 million pascals
With linear sequential arrays each crystal is about ______ in width and the array is up to _______ long.
-1 wavelength -10 cm
In biologic media typical values for impedance range from _____ or ______.
-1,250,000 to 1,750,000 rayls -1.25 to 1.75 Mrayls
When the intensity is reduced to 1/10 its original value the relative change is ______.
-10 dB
When the intensity is reduced to 1/10 the relative change is ______.
-10 dB
A convex array has _______ shaped strips of piezoelectric material arranged _________ in a _______ line.
-120-250 rectangular -Side by side -Bowed
A linear sequential array has _________ of piezoelectric material arranged _______ in a _______.
-120-250 rectangular shaped strips -Side by side -Line
In clinical imaging frequency ranges approximately from ______ to ______.
-2 MHz -10 MHz
If the time of flight is 26 ,us the reflector depth is _____ and the total distance traveled is ______.
-2 cm -4 cm
An annular array comprising 4 ringed elements transmits ______ down each scan line, each with a different _______.
-4 pulses -Focal depth
A 3D sonographic image that is real-time is termed _____. The fourth dimension is _____.
-4D -Time
In the body, the speed of sound ranges from _______, depending on __________.
-500 m/s to 4000 m/s - the tissue through which it is traveling
What are the 3 bigness parameters?
-Amplitude -Power -Intensity
Demodulation is also called what two things?
-Amplitude detection -Envelope detection
An ______ produces a beam that is symmetric about the beam axis. Therefore, it's lateral resolution is _____ its elevational resolution.
-Annular array transducer -Equal to
Dynamic receive focusing is performed _______ and ______ controlled by the sonographer.
-Automatically -Is not
Color Doppler displays _____ values, not _____ values
-Average -Peak
What are the 4 distinct alterations a sound beam undergoes when focused?
-Beam diameter in the near field and focal zone is reduced -Focal depth is shallower -Beam diameter in the far zone increases -Focal zone is smaller
What is the prefix, symbol, and meaning of the exponent 10 to the -2nd power?
-Centi -c -Hundredth
PZT is also known as what 3 things?
-Ceramic -Active element -Crystal
The rate at which the power decreases as sound propagates depends on the _______ and the ______.
-Characteristics of the medium -Wave
Harmonics reduces _____ and _____.
-Clutter -Side lobe artifacts
Sound propagates through tissue as a series of _______ and ______.
-Compressions -Rarefactions
In sound propagation molecules oscillate back and forth creating a series of _____ and _____.
-Compressions -Rarefactions
Sound propagates through tissue as a series of ______ and _____. Particles in the medium are pushed together during ______ and pulled apart during ______.
-Compressions -Rarefactions -Compression -Rarefaction
What 2 physical principles always apply to reflection with oblique incidence?
-Conservation of energy -Reflection angle = incident angle
As a sound beam strikes a boundary energy is ______ and what equation applies?
-Conserved - 100% = IRC (%) + ITC (%)
As imaging depth increases transmit time remains _______ while listening time is ______.
-Constant -Prolonged
When the frequencies of the waves differ, both ______ and ______ occur.
-Constructive interference -Destructive interference
What is the prefix, symbol, and meaning of the exponent 10 to the 1st power?
-Deca -da -Ten
What are the prefixes and abbreviations for Tens and Tenths?
-Deca and Deci -da and d
What is the prefix, symbol, and meaning of the exponent 10 to the -1st power?
-Deci -d -Tenth
Attenuation is measured in ______ and reported as a ______ change not as an ______ change.
-Decibels -Relative -Absolute
What are the three consequences of using backing material?
-Decreased sensitivity -Wide bandwidth -Low quality factor
Negative decibels describe signals that are ______ in strength or getting ______.
-Decreasing -Smaller
Impedance increases if _______ is increased or ______ is increased and is also affected by ______ and is not affected by _______.
-Density -Propagation speed -Stiffness -Frequency
When in interaction is disorganized, the sound back to the transducer is _______ or _______.
-Diffuse -Backscatter
The degree of stiffness may also be described by these 2 terms:
-Elasticity -Compressibility
Focal depth is also known as what 2 things?
-Focal length -Near zone length
Treat conversion units as ______ and ______ the units.
-Fractions with a value of 1 -Carry along
Total attenuation depends upon what 3 things?
-Frequency of the sound -Distance the beam travels -The tissue through which the sound wave travels
_____ distances prolong the time-of-flight and ______ distances shorten the time-of-flight.
-Greater -Smaller
What is the prefix, symbol, and meaning of the exponent 10 to the 2nd power?
-Hecto -h -Hundred
What are the prefixes and abbreviations for Hundreds and Hundredths?
-Hecto and Centi -h and c
What are the 2 characteristics of damping material?
-High degree of sound absorption -Acoustic impedance similar to PZT
Damage to one of the elements of a phased array transducer results in ______ or _____ beam steering and ________.
-Inconsistent -Erratic -Focusing
As frequency _____ wavelength ______.
-Increases -Decreases
Positive decibels report signals that are ______ in strength or getting _______.
-Increasing -Larger
What are the temporal intensities from largest to smallest?
-Itp -Imax -Ipa -Ita
What are 2 characteristics of less divergence?
-Larger diameter -Higher frequency
Sound is a _____ wave in which particles in the medium move. The molecules in the medium vibrate back and forth from a _____ position.
-Mechanical -Fixed
What is the prefix, symbol, and meaning of the exponent 10 to the 6th power?
-Mega -M -Million
Speed is measured in?
-Meters per second -mm/,us -Any distance divided by time
What is the prefix, symbol, and meaning of the exponent 10 to the -6th power?
-Micro -,u -Millionth
What is the prefix, symbol, and meaning of the exponent 10 to the -9th power?
-Nano -n -Billionth
Oblique means ______ or _______.
-Not at right angles -Non-perpendicular
A single bit can only represent two values, ____ and _____.
-On -Off
Initially intensity is determined _______, the ultrasound system. However intensity _____ as sound propagates through the body.
-Only by the sound source -Changes
During a color doppler exam with a linear array transducer the color doppler portion of the image is __________ shaped because the electrical spike patterns creating the doppler sound beams are _________.
-Parallelogram -Sloped
Attenuation is determined by what two factors?
-Path length -Frequency of sound
Frequency affects _____ and ______.
-Penetration -Image quality
What are 3 other names for half-value layer?
-Penetration depth, -Depth of penetration -Half-boundary layer
Coefficients are reported as _____ without _____.
-Percentages -Units
_____ colorized the amplitude of the reflected Doppler signal. This brightness of the colors is related to the number of ______.
-Power Doppler -Red blood cells
Intensity relates to how the _______ or is _______.
-Power in a wave spreads -Distributed in space
Demodulation is accomplished by _____ and _____ (filtering).
-Rectification -Smoothing
Sound waves in lung attenuate dramatically because of _____ and _______.
-Scattering -Absorption
Gain, TGC, and frame averaging do not affect _______ and therefore do not affect _______.
-Sound transmission -Exposure
What are 2 characteristics of a medium that affect the speed of sound?
-Stiffness -Density
With A-mode strong echoes create ____ spikes whereas weak reflections create _____ spikes.
-Tall -Short
The half-value layer thickness depends on what 2 factors?
-The medium -The frequency of sound
What are the 2 components of pulsed ultrasound?
-Transmit, talking, or on time -Receive, listening, or off time
The duty factor is a ______ number with a value between _____.
-Unitless -0 and 1
The SP/SA factor is ______ with a value of _______.
-Unitless -1 or greater
Depending on the ultrasound system, the PRF control may be called _____, _____, ______, or other terms. Whatever it is called, it controls ______.
-Velocity scale -Velocity range -Flow rate -PRF
In diagnostic ultrasound we are often interested in the degree of _______ or the extent of ______.
-Weakening -Amplification
As sound travels in the body it ______ or ______.
-Weakens -Attenuates
The horizontal axis or ______ runs ______
-X-axis -Side to side
Axial resolution is measured in?
-mm -cm -units of distance
Intensity ranges from?
.01 to 300 W/cm2
The thickness of PZT crystals in diagnostic imaging transducers rage from ______.
.2-1 mm
In clinical imaging typical powers range from _______.
0.004 to 0.090 watts
In clinical imaging axial resolution range from _______.
0.1 to 1.0 mm
For every 13 ,us of go-return time, the object creating the reflection is ______ deeper in soft tissue.
1 cm
The maximum value for duty factor is?
1 or 100%
The typical value of pulse repetition frequency is?
1,000 to 10,000 hertz
Which of the following statements about formation of the color Doppler image is TRUE? A: The color and B-mode images are generally derived from the same pulse B: The color image is superimposed on top of the existing B-mode image C: The color and B-mode images are generally formed using the same frequency sound wave D: The B-mode image is usually obtained at a lower frequency than the color image E: The color image generally has a higher spatial resolution compared to the B-mode image
B: The color image is superimposed on top of the existing B-mode image
With linear phased array the width of each element is _______ of the sounds wavelength.
1/4 to 1/2
The acoustic footprint of a convex array transducer may be as long as _____.
10 cm
When the intensity is 10 times larger the relative change is ______.
10 dB
The time differences between electrical spikes is about _______.
10 nanoseconds
The typical value of pulse duration in diagnostic ultrasound is?
100 microseconds to 1 millisecond
Pulse repetition period is generally about _______ than pulse duration.
100 to 1000 times longer
When the depth of view is set to 10 cm, PRP is?
130 ,us
When frequency doubles, Rayleigh scattering is?
16 time greater
Frequencies greater than _____ are ultrasonic.
20,000Hz
The audible frequency range of sound is from approximately _______.
20Hz-20,000Hz
When a reflector is 2cm deep, a pulses time-of-flight is _____.
26 ,us
When the intensity doubles the relative change is _____.
3 dB
The speed of sound in bone tissue is?
3,500 m/s
The speed of sound in the lung tissue is?
500 m/s
What can you do to improve visualization of distal acoustic shadowing from calcification? A: Compound imaging B: Tissue harmonic imaging C: Speckle reduction imaging D: 3D imaging E: Tomographic ultrasound imaging
B: Tissue harmonic imaging
When color Doppler is active, how many pulses per scan line are typically used to create the underlying B-mode image? A: 1-2 B: 3-4 C: 5-6 D: 7-8 E: 9-10
A: 1-2
What conditions below are most likely to result in turbulent flow? A: 5 mm vessel with 300 cm/sec flow velocity B: 2 mm vessel with 300 cm/sec flow velocity C: 2 mm vessel with 30 cm/sec flow velocity D: 1 mm vessel with 30 cm/sec flow velocity E: 4 mm vessel with 30 cm/sec flow velocity
A: 5 mm vessel with 300 cm/sec flow velocity
Which transducer will detect the largest Doppler frequency shift? See image for question #457 A: A B: B C: C D: D E: E
A: A
Which type of transducer should you select to produce the narrowest slice thickness throughout the image plane? A: A 1.5D multi-row array B: A phased array with a small footprint C: A tightly curved curvilinear array D: A mechanical sector E: A mechanically rocked 3D transducer
A: A 1.5D multi-row array
What is an advantage of using high-PRF Doppler? A: Ability to measure high velocities B: Improved range resolution C: Higher frame rate D: Greater sensitivity to slow flow E: Improved spatial resolution
A: Ability to measure high velocities
Which of the following parameters relates to tissue heating? A: Absorption B: Impedance C: Refraction D: Propagation speed E: All of the above
A: Absorption
What term describes the Hyperechoic region (arrow) seen beneath this complex structure? A: Acoustic enhancement B: Acoustic shadowing C: Reverberation D: Refraction E: Acoustic impedance See image for question #67
A: Acoustic enhancement
A hydrophone measures: A: Acoustic pressure output B: Doppler accuracy C: Penetration D: Contrast resolution E: Measurement accuracy
A: Acoustic pressure output
Interference patterns of reflected waves causes: A: Acoustic speckle B: Acoustic enhancement C: Rarefaction D: Volume averaging E: All of the above
A: Acoustic speckle
The salt and pepper appearance you observe in this ultrasound image is a result of: See image for question #412 A: Acoustic speckle B: Compound imaging C: Harmonic imaging D: Electromagnetic interference E: Refraction
A: Acoustic speckle
The motion of particles in a fluid is sometimes observed in an intense ultrasound beam. This is termed: A: Acoustic streaming B: Transient cavitation C: Thermal interaction D: Rarefaction E: Compression
A: Acoustic streaming
This Doppler waveform can be most accurately described as exhibiting: See image for question #472 A: Aliasing B: Spectral broadening C: Mirror image D: Bidirectional flow E: Saturation
A: Aliasing
According to the Doppler equation, for any given velocity, the frequency shift will increase by increasing the: A: Doppler angle B: Transmit frequency C: Pulse length D: Pulse repetition frequency E: All of the above
B: Transmit frequency
The maximum cyclical change in a quantity is known as: A: Amplitude B: Pressure C: Power D: Intensity E: Decibel
A: Amplitude
How many levels of information can a single bit represent? A: One B: Two C: Four D: Eight E: Sixteen
B: Two
What type of transducer could you choose to produce a beam that is symmetrical about the beam axis? A: Annular array B: Linear sequenced array C: Phased array D: Curved array E: Tightly curved array
A: Annular array
What transducer component is designed to control ringing of the piezoelectric element? A: Backing material B: Electrical insulator C: Matching layer D: Radiofrequency shield E: Lens
A: Backing material
What part of the sonographic instrument is responsible for Apodization, beam steering, focusing, and aperture control? A: Beam former B: Receiver C: Memory D: Pulser E: Scan converter
A: Beam former
What technique would be most likely to produce grating lobes in your image? A: Beam steering B: Tomographic ultrasound imaging C: 3D imaging D: Speckle reduction imaging E: Tissue harmonic imaging
A: Beam steering
In this image the color green represents: See images for question #528 A: Aliasing B: Variance C: Negative Doppler shift D: Laminar flow E: Parabolic flow
B: Variance
What should be done to improve the Doppler waveform in the previous question? See image for question #385 A: Change the Doppler angle B: Decrease the Doppler gain C: Increase the PRF D: Reposition the sample volume E: Decrease the sample volume length
A: Change the Doppler angle
What control allows the user to freeze and then scroll back through the most recently acquired image frames? A: Cineloop B: Read zoom C: Write zoom D: Archive E: Preprocessing
A: Cineloop
What parameter describes the axial length of the sampling volume for a color pixel? A: Color gate B: Packet size C: Pulse repetition frequency D: Pulse repetition period E: Line density
A: Color gate
In sound wave propagation a region of elevated pressure is termed: A: Compression B: Demodulation C: Rarefaction D: Period E: Resonance
A: Compression
Which control would you adjust to alter the dynamic range of the displayed echoes? A: Compression B: Transmit power C: Scanning depth D: Time gain compensation E: Focusing
A: Compression
An interaction of echoes that leads to reinforcement rather than to partial or total cancellation is known as: A: Constructive interference B: Refraction C: Destructive interference D: Autocorrelation E: Rarefaction
A: Constructive interference
What display method below will help you to demonstrate flow turbulence with color Doppler? A: Autocorrelation B: Variance C: Fast Fourier analysis D: Zero-crossing detection E: Phase quadrature detection
B: Variance
As you perform a sonogram you switch from a 3.5MHz transducer to a 7.0 MHz transducer to image a superficial structure. Compared to the 3.5MHz transducer what will the 7.0MHz attenuation rate and wavelength be? A: Double the attenuation rate, one half the wavelength. B: Double the attenuation rate, double the wavelength. C: One fourth the attenuation rate, one half the wavelength. D: One half the attenuation rate, double the wavelength. E: One half the attenuation rate, one fourth the wavelength.
A: Double the attenuation rate, one half the wavelength.
What imaging artifact is much worse on the left phantom image compared to the right phantom image? See image for question #414 A: Reverberation B: Volume averaging C: Range ambiguity D: Multipath E: Refraction
B: Volume averaging
When sound strikes a Specular reflector at an oblique angle, the angle of reflection is: A: Equal to but opposite the angle of incidence B: Greater than the angle of incidence C: Less than the angle of incidence D: Twice that of the angle of incidence E: The cosine of the angle of incidence
A: Equal to but opposite the angle of incidence
In this image, the red color indicated by the arrow represents: See images for question #527 A: Flow toward the ultrasound transducer B: Flow away from the sound beam C: Turbulent flow D: Aliased flow E: Retrograde flow
A: Flow toward the ultrasound transducer
You have decreased the image sector width. Which of the following will most likely change as a result of this adjustment? A: Frame rate B: Axial resolution C: Elevational resolution D: Dynamic range E: Bandwidth
A: Frame rate
What system control determines the amount of amplification that occurs in the receiver? A: Gain B: Acoustic power output C: Rectification D: Pulse repetition frequency E: Dynamic range
A: Gain
What artifact might you see with an array transducer due to energy that propagates from the transducer in a direction different from the primary beam? A: Grating lobe B: Mirror image C: Reverberation D: Range ambiguity E: Acoustic enhancement
A: Grating lobe
What term is used to describe a 3-dimensional pixel element in 3D sonography? A: Volume point B: Voxel C: Quadrant D: Channel E: All of the above
B: Voxel
Your patient has edema involving the right lower extremity. This may be caused by: A: Increased intravenous pressure B: Decreased venous hypertension C: Decreased venous hypervolemia D: Increased venous hypovolemia E: Increased extra vascular pressure
A: Increased intravenous pressure
What happens when pressure is applied to a piezoelectric crystal? A: It emits an electrical signal B: It increases temperature C: It emits radio waves D: It emits photons E: It becomes phosphorescent
A: It emits an electrical signal
With a 1D linear array, where is the dimension of the sound beam in the out-of-plane dimension the narrowest? A: It is at the point of mechanical focusing. B: It is at the point of electronic focusing. C: The beam is the same width throughout the image. D: It is in the far field. E: It is always located at a depth equal to 1/2 of the transducer aperture.
A: It is at the point of mechanical focusing.
Measuring the lateral width of a target on an ultrasound phantom is most closely related to: A: Lateral resolution B: Contrast resolution C: Elevational resolution D: Axial resolution E: Temporal resolution
A: Lateral resolution
What conclusion can be reached by comparing the rods labeled A and B in this phantom image? See image for question #572 A: Lateral resolution has deteriorated with depth B: Elevational resolution has deteriorated with depth C: Lateral resolution is best with the rods labeled B D: Axial resolution is best with the rods labeled B E: System sensitivity prohibits comparisons between the sets of rods
A: Lateral resolution has deteriorated with depth
The following illustration depicts acoustic pressure vs. distance in a medium in which a sound wave is present. What sound parameter is measured by the length of the bar labeled A in the following illustration? See image for question #224 A: Amplitude B: Wavelength C: Pressure D: Pulse repetition frequency E: Duty factor
B: Wavelength
The "M" in M-mode stands for: A: Motion B: Magnetic C: Megahertz D: Manual E: Maximum
A: Motion
The ______ reduces the length of time the crystal rings.
Backing material
Why are sonographic images usually compressed before sending to PACS? A: Reduce the time to transmit the image B: Increase the spatial resolution of the image C: Preserve measurements with the image data D: Reduce costs by lowering image quality E: Increase the real-time image frame rate
A: Reduce the time to transmit the image
What does the Doppler signal spectral display depict? A: Relative signal power at each frequency in the Doppler signal B: Depth to each vessel C: Volume flow rate D: Transmit frequency E: Acoustic power
A: Relative signal power at each frequency in the Doppler signal
What term describes the ability of an imaging device to separate closely spaced objects? A: Resolution B: Penetration C: Duty factor D: Interference E: Reflection
A: Resolution
An A-mode display looks like a ______.
Big city skyline
Pulse length is determined by:
Both the source and the medium
Wavelength is determined by _________.
Both the source and the medium
What is an advantage of single-crystal or pure wave crystal transducers? A: Wide bandwidth B: Lower frequencies at higher resolution C: Absence of aliasing with pulsed Doppler D: Higher frame rates E: Greater steering angles
A: Wide bandwidth
Occurs when ultrasonic energy is converted into another energy form such as heat.
Absorption
Sound traveling in bone undergoes extensive ______.
Absorption
The principle mechanism of attenuation in air is ______.
Absorption
Both the intensity and power of a wave are proportional to its _____ ____.
Amplitude squared
Angle of incidence = ______
Angle of reflection
The units of flow are?
Any volume divided by time
The _____ in an array is the number of active elements.
Aperture
What does the ALARA principle stand for?
As Low As Reasonable Achievable
The mathematical middle value.
Average
What is the equation for axial resolution in soft tissue?
Axial resolution (mm) = 0.77 x # of cycles in the pulse/ Frequency (MHz)
Appear as a line of dots of varying brightness.
B-modes
10-3 equals: A: 1000 B: 1/1000 C: 1/10,000 D: 100 E: 10
B: 1/1000
When your patient asks you how much longer the ultrasound test will take his voice is in the audible frequency range. Which of the following frequencies is in the audible frequency range? A: 100MHz B: 10kHz C: 10Hz D: 10,000MHz E: 1,000,000 Hz
B: 10kHz
The velocity scale on this color map is 17 cm/s. If the flow direction is at zero degrees to the sound beam axis, the colors on either end of the bar would represent: Images for question #532 A: A peak velocity of 17 cm/sec B: An average velocity of 17 cm/sec C: A peak velocity of 34 cm/sec D: A peak velocity above 17 cm/sec E: A peak velocity below 17 cm/sec
B: An average velocity of 17 cm/sec
What letter represents the strain relief portion of the transducer? See image for question #586 A: A B: B C: C D: D E: E
B: B
Which factor LEAST influences axial resolution? A: Damping B: Beam width C: Frequency D: Pulse duration E: Pulse frequency
B: Beam width
What is the source of the bright echoes indicated by the arrow in this Doppler waveform? See images for question #511 A: Spectral broadening B: Bruit C: Aliasing D: Mirror imaging E: Range ambiguity
B: Bruit
What is the main advantage you will have by choosing a transducer that produces a thin slice over the image plane? A: Improved frame rate B: Decreased volume averaging C: Better axial resolution D: Larger field of view E: Greater penetration
B: Decreased volume averaging
The repetitive pattern seen in the far field of this image is most likely a result of: See image for question #589 A: Damage to the lens or transducer crystals B: Electrical interference pattern C: Damaged connector pins D: Malfunction of the transmitter E: None of the above
B: Electrical interference pattern
If you increase the pulse repetition frequency and leave all other controls unchanged, what will happen? A: Lateral resolution will improve B: Frame rate will increase C: Frame rate will decrease D: Axial resolution will improve E: Frequency will increase
B: Frame rate will increase
What aspect of the Doppler spectrum is color-encoded with color Doppler? A: Amplitude B: Frequency shift C: Power D: Velocity E: Bandwidth
B: Frequency shift
What potential bioeffect occurs through absorption of sound energy by tissue? A: Cavitation B: Heating C: Attenuation D: Reflection E: Refraction
B: Heating
What is the relationship of frequency to absorption? A: If frequency is halved, absorption is doubled. B: If frequency is doubled, absorption is doubled. C: If frequency is doubled, absorption is halved. D: If frequency is halved, absorption is quartered. E: The rate of sound absorption is not frequency dependent.
B: If frequency is doubled, absorption is doubled.
These B-mode images of the common carotid artery show a graphic overlay indicating the number of lines of sight used to acquire each frame of information. No other system parameter was adjusted. Which statement below is true comparing image A to image B? See image for question #389 A: Image A has a frame rate higher than image B B: Image A has better lateral resolution than image B C: Image A has better axial resolution than image B D: The temporal resolution is better in image A than in image B E: The PRF in image A is lower than that in image B
B: Image A has better lateral resolution than image B
You are performing a sonographic exam with a wide-bandwidth transducer. The advantage you obtain with this transducer compared to narrow-band transducer is: A: Decreased acoustic power output B: Improved axial resolution C: Improved lateral resolution D: Improved focusing E: Wide-bandwidth transducers can be autoclaved
B: Improved axial resolution
One MHz equals: A: 10 3 Hz B: 10-3 Hz C: 10 6 Hz D: 10-6 Hz E: 10 9 Hz
C: 10 6 Hz
Which operator control most directly adjusts the intensity of the transmitted pulse? A: Receiver gain B: Depth of scanning C: Acoustic output (transmit) power D: Time gain compensation (TGC) E: Pulse repetition frequency
C: Acoustic output (transmit) power
Which artifact is related to beam attenuation? A: Comet tail B: Aliasing C: Enhancement D: Reverberation E: Side lobe
C: Enhancement
Which of the following contributes to improve the elevation resolution in a B-mode image? A: Increased transmit power B: Increased bandwidth C: Focusing with an acoustic lens D: Increased dynamic range E: Beam steering
C: Focusing with an acoustic lens
Which of the following transducer types is best suited to cardiac imaging? A: Mechanical sector B: Linear array C: Phased array D: Convex array E: Annular array
C: Phased array
What sound-tissue interaction is necessary to form an ultrasound image? A: Rarefaction B: Refraction C: Reflection D: Diffraction E: Interference
C: Reflection
What can you do to improve contrast resolution in the ultrasound image? A: Increase the sector width B: Decrease the number of focal zones C: Use a 2D or matrix array transducer D: Use a phased array transducer E: Use a curved array transducer
C: Use a 2D or matrix array transducer
The combination of the active element, wire, and system electronics.
Channel
With internal focusing a _______ concentrates the sound energy into a narrower or tighter beam.
Curved piezoelectric crystal
The "A" in A-mode stands for? A: Average B: Attenuation C: Aperture D: Amplitude E: Acoustic
D: Amplitude
As depth of view decreases, pulse repetition period _______.
Decreases
The loss of piezoelectric properties is called ______.
Depolarization
The angle at which the Doppler beam intersects the blood flow.
Doppler angle of incidence
The velocity estimation in Doppler ultrasound is based on measurement of the _______.
Doppler angle of incidence
The time that the sound beam is actually on.
Duty factor
You are imaging a rounded mass with irregular borders. The mass has a much slower propagation speed than surrounding tissue. What sound tissue interaction will be encountered as the ultrasound propagates through this interface? A: Refraction B: Reflection C: Absorption D: Scattering E: All of the above
E: All of the above
You have increased the transmit power while performing a pelvic ultrasound examination. This action increases which of the following? A: Penetration B: Acoustic power C: Image brightness D: Voltage applied to the transducer elements E: All of the above
E: All of the above
You may observe a mirror image artifact with which imaging mode? A: B-mode B: Spectral Doppler C: Color Doppler D: Power Doppler E: All of the above
E: All of the above
Which of the following would increase the spatial pulse length? A: Increased PRF B: Decreased number of transmit pulses per frame C: Increased number of transmit pulses per second D: Increased number of transmit pulses per line E: Increased number of cycles per pulse
E: Increased number of cycles per pulse
The time that is takes for one pulse to occur is known as the: A: Duty factor B: Spatial pulse length C: Wavelength D: Pulse repetition frequency E: Pulse duration
E: Pulse duration
Where are images stored in the ultrasound system? A: Pulser B: Receiver C: Beam former D: Display E: Scan converter
E: Scan converter
Which of the following describes sound propagation through a vacuum? A: Sound travels as transverse waves through a vacuum. B: When sound travels through a vacuum, the propagation speed increases to 3,300,000m/s. C: Sound travels at the speed of light in a vacuum. D: Sound propagation is random in a vacuum. E: Sound cannot travel through a vacuum.
E: Sound cannot travel through a vacuum.
Typically a high-amplitude but low-frequency shift signal.
Flash artifact
Indicates the volume of blood moving during a particular time.
Flow
With linear phased arrays if the electronic pattern is curvature the sound beam is ______
Focusing
____ are a summation of side lobes generated by array transducers.
Grating lobes
If speed 2 is greater than speed 1 the transmission angle will be ______ the incident angle.
Greater than
A number in scientific notation form with a positive exponent has a value ______.
Greater than 10
An obtuse angle is ______.
Greater than 90 degrees
The depth of tissue that results in 3 dB of attenuation to the intensity.
Half-value layer thickness
The distance that sound travels in a tissue that reduces the intensity of sound to one-half its original value.
Half-value layer thickness
Doubling the frequency ____ the period.
Halves
The study of blood moving through the circulatory system.
Hemodynamics
Shorter pulses _____ axial resolution.
Improve
Contrast resolution is always improved by _______.
Increasing frequency
Spatial pulse length is ______ to frequency.
Inversely proportional
As long as a wave remains in one medium, wavelength and frequency are ______.
Inversely related
Period and frequency are _____ to eachother.
Inversely related
Two items are associated such that when one item increases, the other decreases.
Inversely related or proportional
Measured over the entire cross-sectional area of the sound beam and over all time.
Isata
An acute angle is ______.
Less than 90 degrees
The operational characteristics of convex arrays are similar to those of _________ arrays.
Linear
Only the ______ portion of the pulse repetition period is changed when the sonographer alters imaging depth.
Listening (receive) time
The transducer is receiving signals from reflectors in the body during the _______.
Listening time
_____ frequencies are best to use for scanning a large patients abdomen.
Lower
A sloped pattern excites the ______ active element first.
Lowest
Sound energy is _____ intense at the focal point.
More
The primary advantage of annular phased arrays is that ________ create each scan line of the image.
Multiple transmit focal zones
To increase by a factor means to ______.
Multiply
Is the period adjustable?
No
The y-axis in b-mode represents?
Nothing
Angles with a measure other than 90 degrees are also called ______ angles.
Oblique
Obtuse angles are ______.
Oblique
The attenuation coefficient is _____ of the frequency.
One half
For a disc shaped crystal the width of the soundbeam at the focus is _______.
One half the width of the beam as it leaves the transducer
The typical value of period in diagnostic ultrasound is ________.
One tenth to one-half of a millionth of one second
The Z axis is also known as?
Out of plane dimension
The maximum value.
Peak
Adjustable focus systems are called _______.
Phased array
Always means adjustable of multi-focus.
Phased array
Means adjustable or multiple focusing.
Phased array
Concentration of force in an area.
Pressure
During ______ the reflected sound pulse is converted into electricity.
Reception
Focusing also occurs during ______.
Reception
Period and frequency have a special relationship called _____.
Reciprocal
The PRP and PRF have a special relationship called ______.
Reciprocal
When two numbers with this are multiplied together, the result is one. This is a special form of inverse relationship.
Reciprocal relationship
A _______ image is created with a linear sequential array transducer.
Rectangular
In general, when the sector angle is decreased, the number of scan lines is ______.
Reduced
Increasing the Doppler angle ______ the Doppler frequency shift for any given velocity.
Reduces
The intensity of the portion of the incident sound beam that, after striking a boundary, returns back in the direction from which it came.
Reflected intensity
Weakens the portion of the sound wave that continues to transmit in the forward direction.
Reflection
The y-axis of the A-mode represents _______.
Reflection amplitude
A bending of the sound beam and occurs whenever the beam strikes an interface where the propagation speed is different between the two media and the angle of incidence is not perpendicular.
Refraction
A bending of the sound beam that results in lateral misregistration of structures posterior to the refracted beam.
Refraction
A change in direction of wave propagation when traveling from one medium to another.
Refraction
A process associated with transmission and occurs with light waves as well as sound waves.
Refraction
Bending of the sound beam.
Refraction
Occurs whenever there is oblique incidence and different propagation speeds between two media.
Refraction
Occurs with oblique incidence and a change in propagation speeds at the interface.
Refraction
Decibels report _______
Relative changes
The average intensity across the beams entire cross-sectional area.
Spatial average intensity or Isa
What does SAPA stand for?
Spatial average, pulse average
What does SATA stand for?
Spatial average, temporal average
What does SATP stand for?
Spatial average, temporal peak
A method in which the sound beam is steered in multiple directions by employing time delays.
Spatial compounding
The beams intensity at the location where it is maximum.
Spatial peak intensity or Isp
What does SPTP stand for?
Spatial peak, Temporal peak
Occurs when the interface is large and smooth.
Specular reflection
Occurs when the surface is smooth and large compared to the wavelength.
Specular reflection
With ______ the angle of reflection is equal to the angle of incidence.
Specular reflection
A large smooth interface such as the renal capsule, diaphragm, or pericardium.
Specular reflector
What is the equation to figure out speed in m/s?
Speed (m/s) = frequency (Hz) x wavelength (m)
The _____ is determined by the medium, not the sound source.
Speed of sound
The spike line is ______ if the spike line has a slope.
Steered
With linear phased arrays if the electronic pattern has a slope the sound beam is _______.
Steering
The destruction of all microorganisms by exposure to extreme heat, chemical agents, or radiation.
Sterilization
Describes the ability of an object to resist compression.
Stiffness
The portion of the transducer that protects the insertion of the cable into the transducer housing.
Strain relief
The brightness of the dot in B-mode indicates the ______.
Strength of the reflection
The focus is located at ________.
The end of the near zone
Period is reported in units of _____.
Time
The sound beam is directed straight ahead when the spike line is _______.
Vertical
The adult brain must be limited to _____ frequencies to enhance penetration.
Very low
Flow is also called?
Volume flow rate
The term _____ is used to describe the smallest element of a 3-dimensional volume.
Voxel
At depths more than two near zone lengths the beam is ______ the active element.
Wider than
As sound travels the ____ of the beam changes.
Width
Lateral resolution is determined by the _________.
Width of the sound beam
Provides an electrical connection between the PZT and the ultrasound system.
Wire
Power is proportional to the wave's _____
amplitude squared
Sound waves are _____ waves.
longitudinal
When the intensity increases 10-fold the relative change is _____.
+10dB
When a waves intensity doubles, the relative change is ______.
+3dB
What are the 2 equations for axial resolution?
- Axial resolution (mm) = spatial pulse length (mm)/2 - Axial resolution (mm) = wavelength (mm) x # of cycles in the pulse/2
The value of the ITC ranges from ______ and is defined by what 2 equations?
-0% to 100% -ITC (%) = Transmitted Intensity/Incident Intensity x 100 -ITC (%) = 1 - IRC
In clinical imaging duty factor ranges from ________ or _______.
-0.002 to 0.005 -0.2% to 0.5%
A transducer with a 3 MHZ frequency produces a sound pulse that has frequencies ranging from _____ and the range of frequencies in the pulse is _______
-1 MHz to 5 MHz -4 MHz
If the time of flight is 13 ,us and the reflector depth is ____ and the total distance traveled is ______.
-1 cm -2 cm
The duty factor is _____ for continuous wave sound, because the system is always ________.
-100% -Transmitting
An 8-bit system produces a maximum of _____ or ____ shades of gray.
-28 -256
If the time of flight is 39 ,us the reflector depth is _____ and the total distance traveled is ______.
-3 cm -6 cm
When the intensity is reduced to half the relative change is _____.
-3 dB
When the intensity is reduced to 1/2 its original value the relative change is ______.
-3dB
If the time of flight is 52 ,us the reflector depth is ______ and the total distance traveled is ______.
-4 cm -8 cm
A-mode displays are created as follows: as a sound pulse is emitted by the transducer, _________. When a reflection returns to the transducer it is ______ and the moving dot is _______ on the screen.
-A dot moves at a constant speed across the systems display -Processed -deflected upward
Attenuation is a process whereby sound energy is extracted from a wave by ______, ______, and ______.
-Absorption -Scattering -Reflection
What are the 3 types of angles?
-Acute -Right -Obtuse
With an _____, the peak of the waveform is clipped off and appears on the opposite side of the baseline. It starts from the bottom of the image and points up toward the baseline. It does not start from the baseline and point down. That would indicate ______.
-Aliased signal -Retrograde flow
For continuous wave ultrasound, the beam is _____, so the _____ and _____ average intensities are the same.
-Always on -pulse -temporal
3 parameters that describe the magnitude or strength of a wave.
-Amplitude -Power -Intensity
What are the three parameters that describe the size or magnitude or strength of a sound wave?
-Amplitude -Power -Intensity
What are the 3 basic modes of display or formats that are important in viewing ultrasound information?
-Amplitude mode -Brightness mode -Motion mode
B-mode displays are created as follows: as a sound pulse is emitted by the transducer, ___________. When a reflection returns to the transducer it is _______ and the ____________.
-An invisible dot moves at a constant speed across the systems display -Processed -Invisible dot is turned on
Lateral resolution is also known as _______, ______, and ______ resolution.
-Angukar -Transverse -Azimuthal
The ______ describes the decreased pressure that occurs at a stenotic site as a result of the increased blood velocity within the stenosis. It is based on maintaining _____ along the vessel.
-Bernoulli effect -Energy balance
A tissues impedance is _______ not _______.
-Calculated -Measured
The rate at which intensity changes as sound propagates depends on the _________ and the _______.
-Characteristics of the medium -Shape of the sound beam
A line in M-mode that moves up and down on the display indicates that a reflector is moving _____ and _______ from the transducer whereas a straight horizontal line indicates a ______ reflector.
-Closer to -Further away -Stationary
To increase the clinical utility of linear array probes, manufacturers have designed arrays with a bowed or curved shape. These transducers are called ______, _______, or ________.
-Convex -Curved -Curvilinear
What are 6 characteristics of non Imaging Transducers?
-Creates continuous wave or pulses with long duration and length -No backing material -Increased sensitivity -Narrow bandwidth -Higher Q factor -Does not even make an image
The temperature at which PZT is polarized.
-Curie temperature -Curie point
What are two other names for convex arrays?
-Curvilinear array -Curved linear array
With B-mode weaker reflections appear as _____ dots whereas stringer reflections appear as ______ dots.
-Darker grey -Brighter white
The matching layer _____ reflections at the PZT/skin boundary thereby _____ the percentage of transmitted sound between the active element and the skin.
-Decreases -Increasing
Speed is determined by the ______ and ______ of the medium.
-Density -Stiffness
When a wave reflects off an irregular surface, it radiates in more than one direction. This form of reflection is called _____ reflection or _______.
-Diffuse -Backscatter
Within the far zone the beam ______ or ______.
-Diverges -Spreads out
Other probes such as those used in therapeutic ultrasound or continuous wave Doppler _____ use backing material and are ______ pulse, _____ bandwidth.
-Do not -Long -Narrow
Non stiff media are described as?
-Elastic -Compressible
All waves carry _____ from one location to another. Many different forms of waves exist, including _____, _____, _____, and _____
-Energy -Heat -Sound -Magnetic -Light
The number of pulses per line is termed _____, ______, and ______.
-Ensemble length -Packet size -Shots per line
Packet size is also know as what two things?
-Ensemble length -Shots per line
What are the 3 methods of focusing?
-External focusing -Internal focusing -Phased array focusing
The image created by a mechanical transducer is _____ or _____ shaped.
-Fan -Sector
The image created by a phased array transducer is ______ or ______ shaped.
-Fan -Sector
The far zone is also known as what 2 things?
-Far field -Fraunhofer zone
What are 2 characteristics that create pulses of short duration?
-Few cycles in the pulse -Individual cycles with short periods
What 2 characteristics create short pulse length?
-Fewer cycles in the pulse -Cycles with shorter wavelengths
Mechanical transducers have a _____ focal depth. This is also referred to as ________, ______, or ______ focusing.
-Fixed -conventional -Mechanical -Fixed
With fixed focusing techniques the ______ and the ______ cannot be changed.
-Focal depth -Extent of focusing
The focal length is also known as what 2 things?
-Focal depth -Near zone length
With an annular phased array the final image is a composite of information from only the _______ of each ______.
-Focal zone -Crystal
What are the 5 terms that describe the shape and regions of a sound beam?
-Focus -Near zone -Focal length -Far zone -Focal zone
When the outer crystals are excited earlier than the inner crystals it has a curved pattern that creates a _____ sound beam. And since there is no slope to this pattern the beam will be directed _______.
-Focused -Straight ahead
What is the prefix, symbol, and meaning of the exponent 10 to the 9th power?
-Giga -G -Billion
What are the prefixes and abbreviations for Billions and Billionths?
-Giga and Nano -G and n
The elapsed time from pulse creation to pulse reception.
-Go-return time -Time-of-flight
The further sound travels, the ______ the attenuation and the _______ the beam becomes.
-Greater -Weaker
The transmission angle will be greater than the incident angle when the speed of Medium 2 is ________ the speed of Medium 1.
-Greater than
Since M-mode ultrasound information arises from a single penetration into the body the sampling rate of M-mode is very ______ and is _______ pulse repetition frequency of the system.
-High -Equal to the
What are the characteristics of a thin half-value layer?
-High frequency sound -Media with high attenuation rate
Duty factor is ______ when the system is imaging at shallow depths, and ______ when imaging to greater depths.
-Higher -Lower
Instruments that penetrate the skin of mucous membranes have the _____ potential for transmitting infections and these instruments require ______.
-Highest -Sterilization
When one ring of annular phased array transducer malfunctions it will appear as a ______ or _______ band of ________ at a particular depth.
-Horizontal -Side-to-side -dropout
Pulse repetition frequency is reported in units of?
-Hz -Per second
Reciprocal numbers are inverse because when one _____, the other ______.
-Increases -Decreases
What are the 2 things the matching layer does?
-Increases the efficiency of sound energy transfer between the active element and the body -Protects the active element
The Reynold's number increases with _____ flow speed and _____ tube diameter.
-Increasing -Enlarging
What are the two methods of fixed focusing?
-Internal focusing -External focusing
Wavelength is ______ to frequency. Doubling the frequency ______ the wavelength.
-Inversely proportional -Halves
______ means that the spatial resolution is equal in all dimensions or imaging planes. ______ is the opposite of this.
-Isotropic resolution -Anisotropic resolution
What is the prefix, symbol, and meaning of the exponent 10 to the 3rd power?
-Kilo -k -Thousand
What are the prefixes and abbreviations for Thousands and Thousandths?
-Kilo and Milli -k and m
The linear sequential array has a _______ footprint and creates ________ images.
-Large acoustic -Rectangular
What are 2 characteristics of a deep focus?
-Larger diameter PZT -Higher frequency
For lateral resolution the mnemonic LATA stands for?
-Lateral -Angular -Transverse -Azimuthal
The piezoelectric materials most commonly used in clinical transducers are ______ or ______.
-Lead zirconate titanate -PZT
What are the 4 characteristics of shallow imaging?
-Less listening -Shorter PRP -Higher PRF -Higher duty factor
A short pulse is created in what 2 ways?
-Less ringing -Higher frequency
Produce beams that are asymmetric.
-Linear array -Phased array -Curved array
What are two other names for phased array transducers?
-Linear phased array transducers - Sector transducers
The _____ or _____ of a number represents the number of 10's that are multiplied to create the original number.
-Logarithm -Log
Thicker active elements create ______ wavelength _____ frequency sound pulses.
-Longer -Lower
Collateral vessels have a _____ length and a ______ diameter, both resulting in ______ resistance to flow.
-Longer -Smaller -Increased
What are the 2 characteristics of more attenuation?
-Longer distances -Higher frequencies
For axial resolution what does LARRD resolution stand for?
-Longitudinal -Axial -Range -Radial -Depth
Axial resolution is also known as what 4 other things?
-Longitudinal -Range -Radial -Depth resolution
Wide bandwidth probes have a ____ Q factor and narrow bandwidth probes have a _____ Q factor n
-Low -High
What are the characteristics of a thick half-value layer?
-Low frequency sound -Media with low attenuation rate
The graph of two directly related items extends from ______ to ______.
-Lower left -Upper right
What is the speed of sound in tissues from lowest to highest?
-Lung -Fat -Soft tissue -Liver -Blood -Muscle -Tendon -Bone
What 2 characteristics create long pulses?
-Many cycles in the pulse -Cycles with longer wavelengths
What are 2 characteristics that create pulses of long duration?
-Many cycles in the pulse -Individual cycles with long periods
The _____ and _____ increase the efficiency of sound transfer between the transducers PZT and the skin.
-Matching layer -Gel
Since the beam steering of an annular phased array transducer is _______, the image is ______ or _____ shaped.
-Mechanical -Fan -Sector
What are the prefixes and abbreviations for Millions and Millionths?
-Mega and Micro -M and ,u
Amplitude is measured from the ______ to the ______.
-Middle value -Maximum value
What is the prefix, symbol, and meaning of the exponent 10 to the -3rd power?
-Milli -m -Thousandth
Higher frequency sound attenuates _______ and is _____ capable of traveling to substantial depths.
-More -Less
What are the 4 characteristics of deeper imaging?
-More listening -Longer PRP -Lower PRF -Lower duty factor
If the innermost ring of an annular phased array transducer malfunctions the ________ region of the image is lost. If an outer ring malfunctions, a ________ of the image is lost.
-Most superficial -Deeper horizontal band
As a general rule long duration events are _______ bandwidth and short duration events are _____ bandwidth.
-Narrow -Wide
The sound beam exits the probe and enters the ______ or _____ zone.
-Near -Fresnel
What are 2 other terms for the near zone?
-Near field -Fresnel zone
If speed 1 is equal to speed 2 there will be _____ refraction and the transmission angle is ______ the incident angle.
-No -Equal to
If the speeds of two media are identical, ________ will occur and the angles of incidence and transmission will be _______. The sound travels _______.
-No refraction -Equal -Straight ahead
During a color doppler exam with a linear array transducer the electrical patterns creating sound beams for the grayscale image have ________ and the sound beams are directed _________.
-No slope -Straight down
Refraction depends on both ______ and different media _____.
-Oblique incidence -Propagation speeds
What are the 2 conditions for refraction?
-Oblique incidence -Different propagation speeds
What is the requirement for refraction?
-Oblique incidence -Different speeds
Refraction occurs only if what two conditions are satisfied?
-Oblique incidence -Propagation speeds of the two media are different
Initially amplitude is determined ________, the ultrasound system. However, amplitude _____ as sound propagates through the body.
-Only by the sound source -Decreases
The _____ control is used by the operator to adjust the magnitude of the voltage pulse applied to the crystal. As it increases, the intensity of the transmitted pulse ______.
-Output power -Increases
By adjusting the imaging depth the operator changes what 3 things?
-PRP -PRF -Duty factor
With linear sequential array transducers the sound beams are _______ to eachother and usually directed ________.
-Parallel -Straight ahead
When linear arrays steer sound beams electronically it creates _________ shaped images rather than _________ images.
-Parallelogram -Rectangular
Duty factor is a ______ and is therefore _______.
-Percentage -Dimensionless
The coefficients IRC and ITC are both reported as ______ and are therefore ______.
-Percentages -Dimensionless
What are the the seven acoustic parameters used to describe the characteristics of a sound wave?
-Period -Frequency -Amplitude -Power -Intensity -Wavelength -Propagation speed
What are the 5 parameters that are initially determined by the sound source only?
-Period -Frequency -Amplitude -Power -Intensity
What are the 4 parameters that describe a single cycle that can describe both pulsed and continuous waves?
-Period -Frequency -Wavelength -Propagation speed
Normal incidence is also known as what 4 different names?
-Perpendicular -Orthogonal -Right angle -90 degrees
M-mode displays are created as follows: as a sound pulse is emitted by the transducer, ____________ and __________ are produced on the paper.
-Photo sensitive paper is moved at a constant speed across a B-mode display -Various squiggly lines that represent the changing depth of the reflecting surfaces
With annular phased array transducers a two dimensional image is built up by ______ rotating the ringed element array so that it transmits sound beams in _______ directions.
-Physically -Different
Materials which convert sound into electricity (and vice versa) are called ______ or ______.
-Piezoelectric -Ferroelectric
Intensity depends on both the ______ and the ________.
-Power in the beam -Area over which the power is applied
If it can't be performed on a frozen image, it is ______. If it can be performed on a frozen image it is ______.
-Preprocessing -Postprocessing
What are the three acoustic variables used to distinguish sound waves from other types of waves?
-Pressure -Density -Distance (particle motion)
What are the 3 forms of flow?
-Pulsatile -Phasic -Steady
The duty factor equation shows that it is related to both ______ and ______.
-Pulse duration -PRP
To determine a duty factor, use a single pair of complete _______ and _______ times.
-Pulse duration -PRP
Damping reduces what 2 things?
-Pulse duration -Spatial pulse length
Axial resolution is determined by the _______, with shorter pulses yielding _______ axial resolution.
-Pulse length -Improved
Axial resolution is improved by reducing _____ or ______.
-Pulse length -Pulse duration
What are 6 characteristics of imaging transducers?
-Pulses with short duration and length -Uses backing material to limit ringing -Reduced sensitivity -Wide bandwidth -Lower q-factor -Improved axial resolution
Decibels are a _____. The actual level is divided by the _______.
-Ratio -Starting level
Impedance is measured with units of _____ and is often represented by the letter _____.
-Rayls -Z
______ focusing is achieved dynamically by introducing electrical delays in the signals returning from the transducer elements to the ultrasound system following echo reception. The delays change _______ during reception of the echoes thereby altering the ___________ variably.
-Receive -Continuously -Receive focal depth
A _______, _______, _______ image is created during color doppler exams with a linear array transducer.
-Rectangular -Grayscale -Anatomic
All Doppler systems are set up so that positive Doppler shifts are color-encoded _____ and negative Doppler shifts are color-encoded _____.
-Red -Blue
What 3 processes contribute to attenuation?
-Refection -Scattering -Absorption
_____ and ____ give rise to the echoes signals that are displayed on the monitor.
-Reflection -Scattering
What is the requirement for transmission?
-Reflection information -The use of the law of conservation of energy
In diagnostic ultrasonography sound pulses travel through media. ______ arising from structures in the body return to the transducer and are processed into ______.
-Reflections -Images
The y-axis of an M-mode represents ______ which is derived from the ________ of the sound pulse.
-Reflector Depth -Time-of-flight information
The x-axis of a B-mode represents ________ which is derived from the ________ of the sound pulse.
-Reflector depth -Time-of-flight information
The x-axis of an A-mode display represents _______ which is derived from the _______ of the sound pulse.
-Reflector depth -Time-of-flight information
Since the beam is always on with CW ultrasound, SPTA= _____ and SATA= ______.
-SPPA -SAPA
The rank of intensities from largest to smallest is?
-SPTP -Im -SPPA -SPTA -SATA
What are the 6 different methods to measure and report intensities?
-SPTP -SATP -SPTA -SATA -SPPA -SAPA
Because peak measurements are larger than average measurements ______ intensity has the highest value, and _______ has the lowest value.
-SPTP -SATA
Smaller diameter PZT crystals create _______ focus beams whereas larger diameter crystals create ______ focus beams.
-Shallow -Deeper
The inner crystal of an annular phased array transducer creates a ______ focus beam and collects information only from the ______ depths. All other information from the inner crystals sound pulse is _______.
-Shallow -Shallowest -Ignored
Imaging probes are identified as _______ pulse, _____ bandwidth.
-Short -Wide
With axial resolution, lower numerical values indicate _____ pulses and _____ image accuracy.
-Shorter -Improved
Thinner active elements create _____ wavelength, ____ frequency sound pulses.
-Shorter -Higher
Higher frequency sound waves produce _____ pulses which produce ______ images.
-Shorter -More accurate
Superior axial resolution is associated with what 5 things?
-Shorter SPL -Shorter pulse duration -Higher frequencies (shorter wavelength) -Fewer cycles per pulse (Less ringing) -Lower numerical values
What are the 2 characteristics of less attenuation?
-Shorter distances -Lower frequencies
The mechanical transducer contains a _________ active element that is ______ moved.
-Single circular disc-shaped -Physically
For a linear phased array transducer the footprint or the face of the transducer that comes into contact with the skin is a ______ about ______ on each side.
-Small square -1 cm
What are 2 characteristics of more divergence?
-Smaller diameter -Lower frequency
What are 2 characteristics of a Shallow focus?
-Smaller diameter PZT -Lower frequency
Grating lobes cause a _____ of the ultrasound beam and ____ lateral resolution.
-Smearing -Degrade
As a general rule sound travels fastest in ______, slower in ______, and slowest in _______.
-Solids -Liquids -Gases
Initially power is determined only by the ______, the ultrasound system. However power _____ as sound propagates through the body.
-Sound source -Decreases
The rate at which amplitude decreases as sound propagates depends on the characteristics of both the _____ and the _____.
-Sound wave -Medium
What are the 5 key words related to reporting intensities of pulsed waves?
-Spatial -Peak -Average -Temporal -Pulsed
Two forms of reflection ______ and _____ are created in soft tissue depending on the nature of the interface that a sound wave strikes.
-Specular -Diffuse
What are the 2 characteristics of the active element that combine to determine the frequency of sound from a pulsed wave transducer?
-Speed of sound in the PZT -Thickness of the PZT
Sound waves produced by a small active element diverge in a _________shape or __________.
-Spherical -Huygen's wavelet
The V shaped waves produced by very small sources are also known as what 3 things?
-Spherical waves -Diffraction patterns -Huygens wavelets
After a sound wave is received by the transducer, converted into electricity and returned to the ultrasound system it is ______ or ______.
-Strengthened -Amplified
When pulsed and continuous wave sound beams have the same SPTP or SATP intensities, which has the higher SPTA or SATA intensity?
-The continuous wave beam
What are the two intensities required to use decibels?
-The reference or starting level -Actual level at the time of measurement
What are the 2 components of the pulse repetition period?
-The transmit time -The receive time
What are 2 characteristics of low frequency pulsed wave imaging transducers?
-Thicker PZT crystals -PZT with lower speeds
Tissue harmonic imaging produces a _____ beam and ______ contrast resolution.
-Thinner -Improved
What are 2 characteristics of high frequency pulsed wave imaging transducers?
-Thinner PZT crystals -PZT with higher speeds
The ______ or ______ adjusts the brightness of the shade of gray that the color Doppler is allowed to write over.
-Threshold -Priority control
Intensities may be reported in various ways with respect to _____ and _______.
-Time -Space
A more accurate image can be created when the ultrasound receiver introduces _______ to some of the electrical signals during ________.
-Time delays -Reception
Compensation is generally referred to as ______ or _______.
-Time gain compensation (TGC) -Depth gain compensation (DGC)
When units change the _____ does not change, only the _____ changes.
-Total picture -Manner of presentation
What are two factors that combine to determine beam divergence?
-Transducer diameter -Frequency of the sound
With a fixed focus transducer, what 2 factors combine to determine the focal depth?
-Transducer diameter -Frequency of the sound
__________ focusing is achieved with a curved pattern phased excitation of the active elements and the outer elements in the group of PZT crystals are fired _______ than the inner crystals.
-Transmit -Earlier
PRP is ______ to period. It is related only to _______.
-Unrelated -Depth of view
The graph of two inversely related items extends from _____ to _____.
-Upper left -Lower right
The vertical axis or _____ runs _______.
-Y-axis -Up and down
The ____ on the Doppler spectrum is represented by the brightness of the dot. The brighter the dot, the ______ the amplitude of the reflected signal.
-Z-axis -Greater
Wavelength is measured in units of?
-mm -meters -units of length
Lateral resolution is measured in units of ______.
-units of distance
Sound with a frequency of 2 MHz has a wavelength of _____ in soft tissue.
.77 mm
The minimum value of duty factor is?
0%
In clinical imaging spatial pulse length in soft tissues ranges from?
0.1 to 1.0 mm
Wavelength in soft tissue ranges from _______.
0.15 to 0.8 mm
When creating anatomic images duty factors are in the range of _____ indicating that ultrasound systems spend a very small percentage of time _____ and a very large percentage of time ______.
0.2% - 0.5% transmitting receiving
In clinical imaging the half-value layer ranges from?
0.25-1.0 cm
The typical value of pulse duration in diagnostic ultrasound is?
0.3 to 2.0 ,us
Period x Frequency = ?
1
In a convex array each crystal is about _________ in width.
1 wavelength
The speed of sound in fat tissue is ?
1,450 m/s
What is the propagation speed of fat?
1,460 m/s
What is the speed of sound in water?
1,480 m/s
The speed of sound in soft tissue is ______.
1,540 m/s
What is the propagation speed of liver?
1,555 m/s
The speed of sound in blood tissue is?
1,560 m/s
The speed of sound in liver tissue is?
1,560 m/s
What is the propagation speed of blood?
1,560 m/s
The speed of sound in muscle tissue is?
1,600 m/s
What is the propagation speed of muscle?
1,600 m/s
The speed of sound in tendon tissue is?
1,700 m/s
In soft tissue sound with a frequency of 1 MHz has a wavelength of _____.
1.54 mm
How do you figure out the wavelength of other frequency sound waves in soft tissue?
1.54 mm/# of MHz = /w\ in mm
The PZT is ______ thick.
1/2 wavelength
When depth of view is set to 7.7 cm, PRF is ______.
10,000 Hz
At the boundary between two media if the IRC and ITC are added the result equals _____.
100%
With a linear phased array transducer there are as many as _________ that are arranged along the face of the probe.
100-300
A 4-bit system is capable of a maxima of ____ shades of gray.
16
What is the log of 100?
2
In clinical imaging a pulse typically contains ______ cycles.
2 to 4
What is the speed of sound in metals?
2,000 to 7,000 m/s
Humans can hear sound waves with frequencies between ______.
20 Hz and 20,000 Hz
The impedance of PZT is about _______ than the impedance of skin.
20 times greater
In general, blood flow becomes turbulent at Reynolds numbers exceeding _____.
2000
A 5-bit system is capable of a maximum of ____ shades of gray.
32
What is the speed of sound in air?
330 m/s
When a reflector is 3 cm deep, a pulses time-of-flight is _____.
39 ,us
The speed of sound in most piezoelectric material ranges from ______.
4 to 6 mm/,us
What is the propagation speed of bone?
4,080 m/s
The reflected signal from Rayleigh scatterers increases to the ____ of the frequency.
4th power
When the depth of view is set to 15.4 cm, PRF is ______.
5,000 Hz
When the depth of view is set to 5 cm, the PRP is ______.
65 ,us
In one second sound can travel into tissue and return from a depth of ______.
77,000 cm
Appears as a series of upward spikes.
A modes
How many lines of sight are sampled and displayed on the monitor in A-mode? A: 1 B: 2 C: 10 D: 256 E: 525
A: 1
Thermally induced biological effects should be preventable by avoiding a local tissue temperature increase exceeding: A: 1 degree C B: 4 degrees C C: 10 degrees C D: 95 degrees F E: None; thermal effects have no threshold.
A: 1 degree C
Which sound beam frequency would exhibit the greatest intensity loss with increasing depth? A: 10MHz B: 8 MHz C: 5 MHz D: 3 MHz E: 2 MHz
A: 10MHz
Which transducer would provide the longest near-zone length? A: 10MHz, 6mm diameter aperture B: 10MHz, 5mm diameter aperture C: 10MHz, 4mm diameter aperture D: 10MHz, 3mm diameter aperture E: 10MHz, 2mm diameter aperture
A: 10MHz, 6mm diameter aperture
You are performing a sonographic exam on a large patient. Which transducer would provide the least amount of signal attenuation? A: 2.5MHz B: 3.5MHz C: 5.0MHz D: 7.5MHz E: 10 MHz
A: 2.5MHz
You have selected a wide-bandwidth transducer with multiple transmit frequencies to perform a sonographic examination. Which transmit frequency should you select for maximum penetration? A: 3.0MHz B: 3.5MHz C: 4.0MHz D: 5.0MHz E: Penetration is not affected by frequency
A: 3.0MHz
What is meant by the term 4D imaging in sonography? A: 3D imaging with the addition of time B: 3D imaging with rendering C: 3D imaging with transparent views D: 3D imaging with tomographic views E: 3D imaging with rotational movie
A: 3D imaging with the addition of time
Which statement about the two pulse trains displayed below is true? Each represents a signal versus time. See image for question #116. A: A has a lower frequency than B. B: B has a longer period than A. C: A has a shorter wavelength than B. D: A has better axial resolution than B. E: a has a shorter spacial pulse length than B.
A: A has a lower frequency than B.
Which of the following describes sensitivity? A: Ability of the system to detect weak echoes B: Ability of the system to demonstrate highly reflective interfaces C: Ability of the system to differentiate between two different structures with slightly varying amplitudes D: Ability of the system to distinguish between two closely spaced structures parallel to the beam E: Ability of the system to distinguish between two closely spaced structures perpendicular to the beam
A: Ability of the system to detect weak echoes
You are imaging a structure containing two media having the same acoustic impedance. What will occur at the boundary of the two structures? A: All of the sound will be transmitted. B: All of the sound will be reflected. C: Some of the sound will be refracted. D: Some of the sound will be reflected and some of the sound will be transmitted. E: Most of the sound will be absorbed at the media boundary.
A: All of the sound will be transmitted.
Varying the excitation voltage to each element in the group used to form the ultrasound pulse is called: A: Apodization B: Dynamic aperture C: Interelement isolation D: Subdicing E: Rectification
A: Apodization
In this illustration, letter C is demonstrating what type of resolution? See image for question #426 A: Axial B: Lateral C: Elevation D: Contrast E: Temporal
A: Axial
If the number of cycles in the transmitted pulsed wave is increased: A: Axial resolution is degraded B: Lateral resolution is degraded C: Spatial pulse length becomes shorter D: Rate of attenuation is increased E: Penetration is decreased
A: Axial resolution is degraded
Which of the following artifacts is the result of reverberation? A: Comet tail B: Acoustic speckle C: Beamwidth D: Refraction E: All of the above
A: Comet tail
The fact that the volumetric flow rate must be the same proximal, at, and distal to a stenosis is termed the: A: Continuity rule B: Reynolds number C: Poiseuille's law D: Bernoulli effect E: Nyquist limit
A: Continuity rule
You obtained a 3D sweep in an axial plane and are viewing it in a multi planar display. What orthogonal planes will be displayed? A: Coronal and Sagittal B: Transverse and coronal C: Transverse and Sagittal D: Oblique planes at 90 degrees E: Oblique planes at 60 degrees
A: Coronal and Sagittal
What maintenance issue is demonstrated in this image? See image for question #590 A: Damage to the lens or transducer crystals B: Electrical interference pattern C: Damaged connector pins D: Malfunction of the transmitter E: None of the above
A: Damage to the lens or transducer crystals
Which best describes the effect of damaged transducer elements in the B-mode image? A: Dark vertical bands beginning at the top of the image B: Bright image C: Cold transducer D: Decreased frame rate E: Horizontal banding
A: Dark vertical bands beginning at the top of the image
Spectral analysis is used to: A: Determine the distribution and magnitude of frequency shifts in the reflected Doppler signal B: Eliminate aliasing from the reflected signal C: Color-encode the Doppler frequency shift D: Eliminate low-frequency shifts from the display E: Determine the velocity of the moving reflector
A: Determine the distribution and magnitude of frequency shifts in the reflected Doppler signal
When you image a structure that is a specular reflector the strength of the received signal depends on the following two factors: A: Difference in acoustic impedance and angle of incidence. B: Difference in acoustic velocity and interface size. C: Difference in acoustic velocity and motion of reflector. D: Angle of incidence and tissue temperature. E: Bulk modulus and interface size.
A: Difference in acoustic impedance and angle of incidence.
While scanning a curved structure, you notice shadowing at the lateral edges of the structure. What is required for this artifact to occur? A: Different media propagation speeds B: Perpendicular incidence C: Transmit frequency exceeding 5 MHz D: Fluid-filled structure in the path of the beam E: Phased array transducer
A: Different media propagation speeds
During Doppler interrogation of the carotid artery, you detect spectral mirroring. Which of the following is a common cause of this artifact? A: Doppler angle of interrogation near 90 degrees B: Doppler angle of interrogation near 0 degrees C: Wall filter set to high D: PRF set too low E: Doppler gain set too low
A: Doppler angle of interrogation near 90 degrees
If you increased the Doppler angle during an exam, what would be the expected result? A: Doppler frequency shift would decrease B: Aliasing would be increased C: Flow velocity would increase D: Sound velocity would increase E: None of the above
A: Doppler frequency shift would decrease
What type of focusing is performed by delay circuitry upon reception? A: Dynamic receive focusing B: Elevational focusing C: Transmit focus D: Multizone transmit E: Mechanical focusing
A: Dynamic receive focusing
This image was obtained with a linear array transducer. The trapezoidal field of view increases the field of view. How is the trapezoidal shape created? See image for question #244 A: Electronic beam steering B: Side lobes C: Grating lobes D: Mechanically steering the elements E: Mirror
A: Electronic beam steering
The most numerous cells in the blood are the: A: Erythrocytes B: Leukocytes C: Platelets D: Plasma E: Lymphocytes
A: Erythrocytes
The thermal index indicates: A: Estimated maximum temperature increase in tissue B: Minutes of exposure time before heating is too great C: Seconds of exposure time before heating is too great D: Acoustic power in milliwatts E: Liklihood of cavitation
A: Estimated maximum temperature increase in tissue.
The propagation speed for sound is lowest in which of the following biological tissues? A: Fat B: Blood C: Muscle D: Bone E: Liver
A: Fat
According to Poiseuille's equation, what will happen to flow if pressure difference increases? A: Flow rate will increase B: Flow will stagnate C: Flow will become Pulsatile D: Flow velocity will decrease E: Flow will become turbulent
A: Flow rate will increase
Which of the following best describes the F number? A: Focal length divided by the aperture B: Aperture multiplied by the number of elements in the transducer C: Number of transducer elements divided by the Fraunhofer zone D: Beam width 1cm from the transducer surface E: Focal length multiplied by the number of elements in the transducer
A: Focal length divided by the aperture
You can reduce beam width to improve spatial resolution in the image by which of the following? A: Focusing B: Decreasing aperture C: Decreasing transducer diameter D: Decreasing transducer width E: Increasing backing material
A: Focusing
Choose two benefits of tissue harmonic imaging. A: Grating lobe artifacts are reduced and lateral resolution is improved. B: Axial and lateral resolutions are improved. C: Contrast and axial resolution are improved. D: Penetration is improved and axial resolution is improved. E: Penetration is improved and contrast resolution is improved.
A: Grating lobe artifacts are reduced and lateral resolution is improved.
This image was obtained with a linear array transducer that employs phasing to steer the beam. What artifact do the arrows point to? See image for question #416 A: Grating lobes B: Reverberation C: Mirror image D: Slice thickness E: Multipath reflections
A: Grating lobes
With absorption acoustic energy is converted to: A: Heat B: Microbubbles C: Kinetic energy D: Decibels E: Potential energy
A: Heat
What Doppler control removes frequencies below a given threshold, resulting in a clean zero baseline? A: High pass filter B: PRF C: Gain D: FFT E: Dynamic range
A: High pass filter
You are performing a sonographic examination and select the tissue harmonics operating mode. What advantage will you obtain over conventional imaging? A: Improved contrast resolution B: Improved penetration C: Improved temporal resolution D: Improved signal-to-noise ratio E: Increased bandwidth
A: Improved contrast resolution
What would be the most likely result from increasing the transmit frequency of the color Doppler? A: Improved sensitivity to slow flow B: Improved penetration for imaging flow in deep tissues C: Reduced flash artifact obscuring small vessel flow D: Reduced color Doppler aliasing E: Improved visibility of complex flow hemodynamics
A: Improved sensitivity to slow flow
What positive result will occur from increasing the packet size while using color Doppler to evaluate flow? A: Improved signal-to-noise ratio B: Reduced aliasing C: Improved axial resolution D: Improved lateral resolution E: Improved temporal resolution
A: Improved signal-to-noise ratio
Which of the following contributes to improve the lateral resolution in a B-mode image? A: Increased aperture B: Increased bandwidth C: Focusing with an acoustic lens D: Increased dynamic range E: Beam steering
A: Increased aperture
What is the advantage of using multiple transmit focal zones? A: Increased lateral resolution B: Increased temporal resolution C: Increased elevation resolution D: Increased axial resolution E: All of the above
A: Increased lateral resolution
Which of the following properties would result in increased propagation speed of sound through a medium? A: Increased stiffness B: Increased density C: Increased frequency D: Increased distance E: Increased amplitude
A: Increased stiffness
You have decreased the scan line density. What technique will be employed to fill in the empt data between the scan lines? A: Interpolation B: Rejection C: Compression D: Autocorrelation E: Demodulation
A: Interpolation
What benefit would you obtain by choosing a transducer having a large diameter compared to one having a small diameter? A: It can focus at greater depths B: Increases the frequency C: Increases the beam diameter in the far field D: A and C E: All of the above
A: It can focus at greater depths
This waveform was obtained from the center flow channel within the common carotid artery. What term best describes this flow state? See images for question #502 A: Laminar flow B: Turbulent flow C: Reynolds flow D: High resistance flow E: Retrograde flow
A: Laminar flow
When you measure the width of a point target in a tissue-mimicking phantom, you are evaluating: A: Lateral resolution B: Contrast resolution C: Elevational resolution D: Axial resolution E: Temporal resolution
A: Lateral resolution
With a standard one-dimensional linear array transducer, what type of resolution is affected most by electronic focusing and dynamic aperture? A: Lateral resolution B: Contrast resolution C: Temporal resolution D: Axial resolution E: Elevational resolution
A: Lateral resolution
Which of the following transducers creates a rectangular image shape? A: Linear array B: Phased array C: Annular array D: Curved array E: B and C only
A: Linear array
What transducer component reduces reflection at the transducer/skin interface? A: Matching layer B: Lens C: Element D: Backing material E: Radiofrequency shield
A: Matching layer
What is an advantage of using a 3D/4D transducer with an automated sweep compared to a traditional transducer with a freehand sweep? A: Measurement accuracy B: Spatial resolution C: Contrast resolution D: Larger field of view E: Greater scanning flexibility
A: Measurement accuracy
Which of the following best characterizes an ultrasound wave in human tissue? A: Mechanical longitudinal wave B: Radioactive wave C: Transverse rarefactional wave D: Electromagnetic wave E: Electronic piezoelectric wave
A: Mechanical longitudinal wave
What is the main advantage of using a 1 1/2D or multirow array transducer? A: Narrow slice thickness over large part of the scanned volume. B: Increased penetration C: Improved axial resolution D: Faster frame rates E: Smaller footprint
A: Narrow slice thickness over large part of the scanned volume.
What is an advantage of a water-path scanner? A: Near-field reverberations are reduced B: Penetration is increased C: Temporal resolution is improved D: Axial resolution is improved E: Slice thickness is reduced
A: Near-field reverberations are reduced
The spatial resolution of the scan converter is determined by: A: Number of pixels in the scan converter matrix B: Number of bits per pixel C: The post-processing settings D: Brightness and contrast settings of the monitor E: Interpolation scheme
A: Number of pixels in the scan converter matrix
When you select one focal zone, how many pulse/listen cycles are required for each acoustic scan line in one image frame? A: One B: Two C: Four D: Eight E: Sixteen
A: One
You are using a linear array transducer to evaluate the thyroid gland. For standard B-mode imaging, this transducer most likely produces pulses of how many cycles? A: One to three B: Three to six C: Six to nine D: Nine to twelve E: Twelve to fifteen
A: One to three
Which transcode frequency would have the thinnest crystal? A: One with a 15MHz center frequency B: One with a 10MHz center frequency C: One with a 7MHz center frequency D: One with a 5MHz center frequency E: All would have the same crystal thickness
A: One with a 15MHz center frequency
An example of a Specular reflector is: A: Pericardium B: Liver parenchyma C: Red blood cells D: Ascites E: Hematoma
A: Pericardium
You have chosen to enlarge an ultrasound image with a read magnification. Which of the following is NOT related to read magnification? A: Preprocessing B: Increased pixel size C: Performance on a frozen image D: Resolution loss E: B and D only
A: Preprocessing
The control that sets the gray-scale brightness at which color will be displayed instead of gray-scale at a pixel location is termed: A: Priority B: Line density C: Persistence D: Ensemble length E: Scale
A: Priority
A type of sonographic imaging that transmits two pulses of opposite phase in rapid succession so they can be cancelled out upon reception is termed: A: Pulse inversion harmonics B: Compound imaging C: Speckle reduction imaging D: Tomographic imaging E: Panoramic imaging
A: Pulse inversion harmonics
What system component determined the pulse repetition frequency? A: Pulser B: Receiver C: Memory D: Display E: Scan converter
A: Pulser
When you adjust the output power control, you affect the following system component: A: Pulser B: Beam former C: Scan converter D: Memory E: Receiver
A: Pulser
What can be done to reduce the presence of the artifact seen in the previous question? See image for question #416 Answer to question #416: Grating lobes A: Reduce or eliminate beam steering B: Change the angle of incidence C: Dynamic aperture D: Increase number of rows of elements in z-axis E: Decrease number of focal zones
A: Reduce or eliminate beam steering
The technique of frame averaging during real-time acquisition is designed to: A: Reduce random noise B: Decrease pixel size C: Redistribute the gray-scale D: Enhance spatial resolution E: Increase frame rate
A: Reduce random noise
If the frame rate is too slow for adequate temporal resolution, what action could you take to improve frame rate? A: Reduce the number of transmit focal zones B: Increase the scan line density C: Increase the scanning depth D: Decrease the dynamic range E: Reduce the transmit frequency
A: Reduce the number of transmit focal zones
The shadow depicted in this image of a renal stone is primarily a result of the following sound-tissue interaction: A: Reflection B: Refraction C: Destructive interference D: Cavitation E: Diffraction See image for question #64
A: Reflection
The arrow in this image depicts flow below the zero baseline. These echoes represent: See images for question #514 A: Retrograde flow due to post stenotic turbulence B: Aliasing C: Mirror imaging D: Incorrect setting of Doppler gain E: Electronic noise
A: Retrograde flow due to post stenotic turbulence
Which intensity descriptor has the lowest numerical value for the characterization of a pulsed-wave ultrasonic field? A: SATA B: SPTA C: SATP D: SPTP E: These intensity descriptors are only used for continuous-wave ultrasound.
A: SATA
You notice that the image in the far field is less bright compared to the near field. This is due to: A: Sound attenuation B: Propagation speed variation C: Refraction D: Diffraction E: The Doppler effect
A: Sound attenuation
Which describes constructive interference? A: Sound waves are in phase and resulting amplitude is increased. B: Sound waves are in phase and resulting amplitude is decreased. C: Sounds waves are out of phase and resulting amplitude is increased. D: Sound waves are out of phase and resulting amplitude is decreased. E: None of the above
A: Sound waves are in phase and resulting amplitude is increased.
Which of the following is present in this Doppler spectral waveform? See images for question #455 A: Spectral broadening B: Narrow velocity range C: Aliasing D: Mirror imaging E: Range ambiguity
A: Spectral broadening
What system control can you adjust to compensate for the effect of sound attenuation in the body? A: TGC B: Dynamic range C: Frame averaging D: Depth E: Line density
A: TGC or Time Gain Compensation
This Doppler waveform is displayed below the zero baseline. Given the settings displayed in this image, which of the following is true? See images for question #525 A: The direction of flow is toward the beam B: The Doppler shift is negative C: The flow is Antegrade D: The system has malfunctioned E: The Doppler steer direction is incorrect for the vessel being interrogated
A: The direction of flow is toward the beam
The transducer you are using transmits wide-bandwidth pulses whose frequency content is 2-5MHz. Which of the following most correctly describes the reflected echo signals after they have traversed the tissue? A: The echo signals will be shifted down in frequency due to the increased attenuation of higher frequencies. B: The echo signals will be of reduced intensity but will have the same frequency content as the transmitted beam. C: The echo signals will be shifted upward in frequency due to the increased absorption of the lower frequencies. D: Only the center frequency component of the bandwidth will be reflected back to the transducer. E: The echo signal frequency content will be identical to that of the transmitted beam.
A: The echo signals will be shifted down in frequency due to the increased attenuation of higher frequencies.
The term duty factor is defined as: A: The fraction of time the transducer is actively transmitting sound B: The fraction of time the transducer is actively receiving sound C: The fraction of time between the transmitted and received sound pulse D: The fraction of time between transmitted sound pulses E: The fraction of time requires for round trip travel of a sound pulse to one cm in tissue
A: The fraction of time the transducer is actively transmitting sound
What best described the difference between the ultrasound frequencies used for Doppler and for B-mode imaging with a given transducer? A: The frequency for Doppler is usually lower than for imaging B: The frequency for Doppler is usually higher than for imaging C: The transmit pulse for Doppler has a greater bandwidth compared to the bandwidth for imaging D: The frequency for Doppler and for B-mode imaging must be identical for a given transducer E: The frequency for Doppler is usually double that for B-mode imaging
A: The frequency for Doppler is usually lower than for imaging
Spatial pulse length is equal to: A: The wavelength times the number of cycles in the pulse B: The wavelength minus the number of cycles in the pulse C: The wavelength times the axial resolution D: The wavelength times the beam width E: The wavelength divided by two
A: The wavelength times the number of cycles in the pulse
What information is present in the M-mode display? A: Time, motion patter, and amplitude B: Amplitude, frequency, and time C: Motion pattern, and frequency D: Time, motion pattern, and frequency E: Bandwidth, amplitude, frequency, time, and motion pattern
A: Time, motion patter, and amplitude
What is the purpose of curving the transducer elements or applying a lens over the elements? A: To provide focusing in the out-of-plane (elevational) direction B: To reduce the acoustic impedance mismatch between the crystal and skin C: To reduce crystal ringing and improve axial resolution D: To help reduce electronic interference E: All of the above
A: To provide focusing in the out-of-plane (elevational) direction
These two phantom images were obtained with maximum gain and acoustic power using two different transducers. What information can be obtained by this comparison? See image for question #581 A: Transducer A has less penetration than transducer B B: Lateral resolution is best with transducer B C: Axial resolution is best with transducer B D: B and C only E: All of the above
A: Transducer A has less penetration than transducer B
While performing a sonogram to minimize risk to the fetus which imaging mode trade off would be most applicable? A: Use M-mode instead of pulsed-wave Doppler to measure the fetal heart rate. B: Use color Doppler instead of power Doppler to image the umbilical cord. C: Use pulsed-wave Doppler instead of power Doppler to evaluate the fetal heart. D: Use harmonics instead of fundamental to image the fetal spine. E: All of the above.
A: Use M-mode instead of pulsed-wave Doppler to measure the fetal heart rate.
Which best describes the cardiac output? A: Volume of blood pumped by the heart per minute B: Volume of blood in a vertical column C: Quantity of blood moving through the vessel per unit of time D: Maximum flow velocity within the vessel lumen E: Hydrostatic pressure per minute
A: Volume of blood pumped by the heart per minute
Which of the following describe diffuse reflection? A: The reflected beam is scattered in various directions. B: The reflected frequency is altered by the Doppler effect. C: The reflected beam is amplified by the focusing effect of scatterers. D: The reflected beam is weakened by the large acoustic impedance mismatch at the tissue interface. E: There is no reflection at a tissue interface because of a disorganized transmit beam.
A: the reflected beam is scattered in various directions.
The conversion of sound to heat in tissue.
Absorption
The most sizable component of attenuation is _______.
Absorption
Results from decreased attenuation through a fluid-filled structure compared to the adjacent tissue.
Acoustic enhancement
Electrical frequency =
Acoustic frequency
Determined by the density and propagation speed of the medium.
Acoustic impedance
The _____ is an important tissue property that influences the amount of reflection.
Acoustic impedance
What is the equation for figuring out acoustic impedance?
Acoustic impedance= Density x Propagation Speed
A thin barrier of cork or rubber that isolates or uncouples the internal components of the transducer from the case. This prevents vibrations in the case from inducing an electrical voltage in the PZT of the transducer.
Acoustic insulator
The effects of the medium upon the sound wave.
Acoustic propagation properties
Sound waves are also known as _____.
Acoustic waves
If the Doppler signal frequency exceeds 1/2 the PRF, _____ occurs.
Aliasing
Occurs when the frequency shift exceeds 1/2 the PRF.
Aliasing
Occurs when the frequency shift exceeds 1/2 the system pulse repetition frequency (PRF).
Aliasing
____ of the Doppler spectrum is an artifact that occurs with pulsed-wave (PW) Doppler when the frequency shift is greater than 1/2 the Doppler PRF.
Aliasing
_____ occurs because the frequency-shifted signal is not adequately sampled.
Aliasing
With normal incidence, if the two media have the same impedance, _____ incident intensity is transmitted.
All of the
_______ active elements in linear phased array probe are fired to create each sound beam.
All of the
The Y-axis in a-mode represents?
Amplitude
The bigness of a wave. The difference between the maximum value and the average or undisturbed value of an acoustic variable. Also the difference between the minimum value and the average value of the acoustic variable.
Amplitude
The z-axis in b-mode represents?
Amplitude
When discussing relationships between amplitude, power, and intensity, the word squared always follows the word _____.
Amplitude
Ultrasound transducers with large PZT crystals create sound beams that are shaped like ____.
An hourglass
_____ is needed to provide accurate velocity information.
Angle correct
The angle between the incident sound beam and an imaginary line that is perpendicular to the boundary is called the ______.
Angle of incidence
The angle between the reflected sound beam and the line perpendicular to the boundary is called the ______.
Angle of reflection
A round transducer in which the elements are arranged concentrically and creates a cone shaped beam that is symmetric in all dimensions.
Annular array
An array transducer where the elements are arranged as circular rings with a common center.
Annular array
Amplitude can have units of ____ of the acoustic variables.
Any
Oblique incidence occurs when the incident sound beam strikes the boundary at _______.
Any angle other than 90 degrees
What are the units of velocity?
Any distance divided by time
______ begins as a fatty streak within the intimal layer of the vessel wall.
Atherosclerosis disease
A decrease is intensity, power, and amplitude as sound travel is called ______.
Attenuation
Bone absorbs ultrasound energy to a large extent which results in substantial ______.
Attenuation
Includes all sound interactions that result in a weakening of the beam.
Attenuation
The weakening of beam strength is termed _____ and accounts for decreased brightness of the image in the far field compared to the near field.
Attenuation
Anything that increases attenuation will increase the ______.
Attenuation coefficient
Degree of attenuation for each centimeter of sound propagation.
Attenuation coefficient
The number of decibels of attenuation that occurs when sound travels one centimeter.
Attenuation coefficient
What is the equation for figuring out the attenuation coefficient?
Attenuation coefficient (dB/cm) = Frequency (MHz)/2
Sound waves with frequencies between 20 Hz and 20,000 Hz.
Audible
Frequency between 20 Hz and 20kHz.
Audible sound
Describes one measure of the detail found in an image.
Axial resolution
Transducers used for diagnostic ultrasound are dampened to improve _______.
Axial resolution
_____ answers the question: What is the minimum distance that two structures, positioned front-to-back (or parallel to the sound beam), can be apart and still produce two distinct echoes on an ultrasound image?
Axial resolution
What type of transducer will improve the artifact demonstrated in the previous question? Answer to question #414: Volume averaging A: Linear array B: 1.5D or multi-row array C: Mechanical 3D D: Phased array E: Mechanical sector
B: 1.5D or multi-row array
Which transducer will exhibit the LEAST amount of volume averaging? A: Mechanical single element B: 1.5D or multi-row array C: Linear array D: Phased array E: Convex array
B: 1.5D or multi-row array
What is a typical frame rate for B-mode real-time imaging? A: 1-9 kHz B: 10-50 Hz C: 100-200 MHz D: 200-300 Hz E: 0.05-0.9 Hz
B: 10-50 Hz
The elapsed time between the transmitted pulse and the detected echo is 26 microseconds. How far is the interface from the transducer? A: 1 cm B: 2 cm C: 3 cm D: 4 cm E: 5 cm
B: 2 cm
Which technology would be most helpful to obtain accurate anatomic volume measurements? A: 2D imaging B: 3D imaging C: Color Doppler imaging D: Harmonic imaging E: Compound imaging
B: 3D imaging
You are using a 5MHz, 40mm linear array transducer to image a structure. What is the width of the image? A: 20mm B: 40mm C: 60mm D: 80mm E: 120mm
B: 40mm
The intensity transmission coefficient at the interface between two structures equals 1/100. What is the intensity reflection coefficient? A: 0/100 B: 99/100 C: 1/100 D: 100/100 E: 49/100
B: 99/100
Which most correctly describes the sound propagation in a medium? A: In sound propagation, a molecule travels from one end of the medium to another. B: A molecule oscillates back and forth to propagate sound waves but does not move from one end of the medium to another. C: A molecule does not vary its position as a sound wave travels. D: Each molecule expands and contracts to propagate a sound wave through a medium. E: Sound waves cannot travel through a medium.
B: A molecule oscillates back and forth to propagate sound waves but does not move from one end of the medium to another.
You are examining a patient with retrograde flow as demonstrated in this image. What causes the flow to reverse its normal flow direction (arrow)? See images for question #503 A: An increase in pressure has occurred due to stenosis in a distal artery B: A pressure drop has occurred due to a stenosis in a proximal artery C: Loss of energy due to post stenotic turbulence D: A decrease in volume flow due to stenosis in a distal lesion E: Peripheral resistance is increased during diastole due to a proximal lesion
B: A pressure drop has occurred due to a stenosis in a proximal artery
Which type of resolution is best in clinical imaging systems? A: Contrast B: Axial C: Elevational D: Temporal E: Lateral
B: Axial
You are scanning a large mass that is composed primarily of fat. Which of the following are you most likely to encounter? A: Posterior acoustic shadowing caused by increased attenuation through the fat. B: Axial misregistration of objects distal to the mass on the screen due to the slower propagation speed through fat. C: Lateral misregistration of the mass on the screen because of refraction. D: Total reflection of the sound beam caused by a large acoustic impedance mismatch. E: Diffraction of the sound beam due to a virtual small aperture through the mass.
B: Axial misregistration of objects distal to the mass on the screen due to the slower propagation speed through fat.
While imaging a cyst you notice shadowing posterior to each lateral border of the cyst. What is the source of the shadows? A: Redirection of the sound beam at an interface with different propagation speeds and a curved surface. B: Bending of the sound beam due to different media propagation speeds. C: Increased attenuation of the sound beam at the borders of the cyst. D: Lateral misregistration of the cyst due to a multipath artifact. E: Diffraction of the sound beam resulting in a weakened signal at the lateral borders of the cyst.
B: Bending of the sound beam due to different media propagation speeds.
Complete destructive interference of echo reflections will affect the display in the following way: A: Bright white pixel B: Black pixel C: Dark gray pixel D: Light gray pixel E: None of the above
B: Black pixel
The ability to differentiate between two regions having similar echogenicity, such as in this liver image with focal fat, is termed: See image for question #268 A: Temporal resolution B: Contrast resolution C: Axial resolution D: Lateral resolution E: Elevation resolution
B: Contrast resolution
This image shows clear distinction between the gray scale of various structures in the fetal brain. The ability to distinguish similar structures with varying gray scale is termed: See image for question #202 A: Axial resolution B: Contrast resolution C: Lateral resolution D: Temporal resolution E: None of the above
B: Contrast resolution
If you wish to perform a sonogram with the largest possible field of view in both the near field and at depth, what type of array transducer would be most preferable? A: Linear array B: Curved array C: Phased array D: Sector E: Any of the above
B: Curved array
During the performance of a sonogram you would be most likely to encounter refraction in this view: A: Specular reflector B: Curved interface C: Perpendicular incidence D: Rayleigh scatterer E: Refraction is not encountered during an abdominal sonogram
B: Curved interface
A standard for handling and transferring images and medical information between computers is: A: Voxel B: DICOM C: HIPAA D: VPN E: Worklist
B: DICOM
The Hyperechoic region in the previous illustration results from: A: Increased acoustic velocity through a fluid-filled structure. B: Decreased attenuation through a fluid-filled structure. C: Decreased sound absorption in the region distal to the fluid-filled structure. D: A high acoustic impedance mismatch between the cyst and adjacent tissue. E: Bending of the sound beam due to oblique incidence.
B: Decreased attenuation through a fluid-filled structure.
What effect will you see in the image if you increase the reject level? A: Increased number of shades of gray B: Decreased low-level echoes C: Decreased frame rate D: Decreased scanning depth E: Decreased amplitude of the brightest shades of gray
B: Decreased low-level echoes
What is the disadvantage of using multiple transmit focal zones? A: Decreased lateral resolution B: Decreased temporal resolution C: Decreased elevation resolution D: Decreased axial resolution E: All of the above
B: Decreased temporal resolution
Increasing the dynamic range setting affects the ultrasound image by: A: Increasing image brightness B: Decreasing image contrast C: Improving spatial resolution D: Increasing rejection of low-level echoes E: Improving signal-to-noise ratio
B: Decreasing image contrast
What system control converts the numbers stored in memory to proportional voltages that control the brightness on a CRT (cathode ray tube) monitor? A: Analog to digital converter B: Digital to analog converter C: Cathode ray tube D: Receiver E: Pulser
B: Digital to analog converter
Which of the following minimizes the degree to which beam width varies with depth? A: Apodization B: Dynamic aperture C: Coprocessing D: Rectification E: Frame averaging
B: Dynamic aperture
What physical concept allows us to determine the location of an interface by measuring the elapsed time between the transmitted pulsed ultrasound wave and the detected echo from that interface? A: Huygen's principle B: Echo ranging C: Snell's law D: Doppler effect E: None of the above
B: Echo ranging
What method is used to steer the color beam with a linear array transducer? A: Mechanical B: Electronic time delays C: Electronic voltage variations D: Apodization E: The color beam cannot be steered with a linear array transducer
B: Electronic time delays
Which of the following statements describes a phased array transducer? A: Electronically focused in two dimensions and mechanically steered. B: Electronically focused along the length of the array, mechanically focused along the elevational dimension, and electronically steered. C: Electronically focused along the elevational dimension of the array, mechanically focused along the length of the array, and unsteered. D: Mechanically focused in two dimensions and mechanically steered. E: Electronically focused along the width of the array, mechanically focused along the length of the array, and mechanically steered.
B: Electronically focused along the length of the array, mechanically focused along the elevational dimension, and electronically steered.
A study designed to determine if there is an association between an adverse effect in a population and exposure to a particular agent is a(n): A: Case report B: Epidemiological study C: In vitro study D: In vivo study E: Single-incident investigation
B: Epidemiological study
What method is most commonly used to perform spectral analysis for pulsed Doppler? A: Zero-crossing detection B: Fourier analysis C: Reynolds number D: Cross-correlation E: Autocorrelation
B: Fourier analysis
What control could you adjust to improve the signal-to-noise ratio on the image? A: Dynamic range B: Frame averaging C: Gray-scale map D: Edge enhancement E: Receiver gain
B: Frame averaging
What control should you adjust to increase the amplification applied to the color Doppler signal? A: Ensemble length B: Gain C: Scale D: Frame averaging E: Line density
B: Gain
Propagation speed error results in which sonographic appearance? A: Improper lateral position of an echo B: Improper axial position of an echo C: Shadowing behind an echo D: Enhancement behind an echo E: None of the above
B: Improper axial position of an echo
This image exhibits banding. This is a result of: See image for question #413 A: Dead transducer element B: Incorrect TGC C: Incorrect master gain D: Incorrect focal zone position E: Incorrect probe pressure
B: Incorrect TGC
Which of the following actions would decrease color Doppler frame rate? A: Decrease frequency B: Increase line density C: Decrease packet size D: Decrease color box size E: Increase gain
B: Increase line density
In order to focus a sound beam relatively far away from the transducer, it is advantageous to: A: Increase the thickness of the element B: Increase the diameter of the element C: Decrease the width of the element D: Decrease the frequency of the element E: Increase the curvature of the element
B: Increase the diameter of the element
You notice a loss of detail in the lateral dimension of the ultrasound image. What can you do to improve this? A: Decrease the number of focal zones B: Increase the scan line density C: Decrease the transducer frequency D: Increase the frame averaging E: Increase the dynamic range
B: Increase the scan line density
You suspect that bright spot on the B-mode image is a calcification, but a posterior acoustic shadow is not present. How can you best optimize your system to demonstrate a shadow distal to the calcification? A: Move the focal zone well below the Hyperechoic focus. B: Increase the transducer frequency. C: Increase the acoustic power output. D: Increase the dynamic range. E: Decrease the scan line density.
B: Increase the transducer frequency.
Increased tissue heating could occur when you: A: Decrease frequency. B: Increase transmit power. C: Decrease exposure time. D: Decrease pulse repetition frequency. E: All of the above
B: Increase transmit power.
Which of the following contributes to improve the axial resolution in a B-mode image? A: Increased aperture B: Increased bandwidth C: Focusing with an acoustic lens D: Increased dynamic range E: Beam steering
B: Increased bandwidth
According to the Doppler equation, which of the following is NOT true? A: Increasing Doppler frequency will increase the frequency shift B: Increasing Doppler interrogation angle will increase the frequency shift C: Decreasing the reflector speed will decrease the frequency shift D: No frequency shift is detected when the Doppler beam strikes the reflector with perpendicular incidence E: Velocity information can be obtained from the frequency shift if the angle of incidence is known
B: Increasing Doppler interrogation angle will increase the frequency shift
Which action would decrease frame rate? A: Increasing pulse repetition frequency B: Increasing acoustic scan line density C: Decreasing sector width D: Decreasing the number of focal zones E: Decreasing image depth
B: Increasing acoustic scan line density
The algebraic summation of waves leading to patterns of minima and maxima is called: A: Scattering B: Interference C: Absorption D: Refraction E: Diffusion
B: Interference
In the images in the previous question, what technique is used to fill in the empty data between the scan lines? See image for question #389 A: Apodization B: Interpolation C: Dynamic receive D: Subdicing E: Dynamic damping
B: Interpolation
A flow condition in which parallel streamlines of flow are present within a tube is termed: A: Parabolic flow B: Laminar flow C: Aliased flow D: Disturbed flow E: Turbulent flow
B: Laminar flow
In this illustration, letter A is demonstrating what type of resolution? See image for question #426 A: Axial B: Lateral C: Elevation D: Contrast E: Temporal
B: Lateral
What disadvantage is related to the transducer type in the previous question? (Tightly curved array) A: Axial resolution degrades with depth B: Lateral resolution degrades with depth C: Field of view is compromised compared to other transducer types D: Temporal resolution is compromised compared to other transducer types E: Elevation resolution is compromised compared to other transducer types
B: Lateral resolution degrades with depth
Which of the following is NOT a limitation of M-mode scanning? A: Information is obtained along only one line of sight B: Motion lateral to the transducer is not displayed C: Motion axial to the transducer is not displayed D: The two-dimensional shape of a structure is not shown E: All of the above are limitations of M-mode
B: Motion lateral to the transducer is not displayed
During a sonographic examination of a large vessel, a 45 degree beam-to-vessel angle would be called: A: Normal incidence B: Oblique incidence C: Perpendicular incidence D: Snell's incidence E: None of the above
B: Oblique incidence
What term describes the number of pulses that are used to determine the velocity along a color line of sight? A: Color gate B: Packet size C: Pulse repetition frequency D: Pulse duration E: Pulse repetition period
B: Packet size
A method used to improve frame rates with multizone electronic focusing is termed: A: Apodization B: Parallel processing C: F-number focusing D: Low-Q transducers E: None of the above
B: Parallel processing
You are reviewing an ultrasound image that has a sector display format that narrows to a point at the transducer surface. What kind of transducer was most likely used to acquire this image? A: Linear array B: Phased array C: Curved array D: Annular array E: Mechanical sector
B: Phased array
The conversion of an incident pressure wave to an electrical signal is the: A: Curie effect B: Piezoelectric effect C: Doppler effect D: Snell effect E: Huygen's effect
B: Piezoelectric effect
Pulse repetition period is the inverse of: A: Duty factor B: Pulse repetition frequency C: Frame rate D: Pulse duration E: Spatial pulse length
B: Pulse repetition frequency
What system function is limited by the speed of sound in tissue? A: Demodulation B: Pulse repetition frequency C: Voltage amplitude D: Rectification E: Time gain compensation
B: Pulse repetition frequency
What term below describes the rate at which the transmitter applies electronic voltage pulses to the transducer? A: Period B: Pulse repetition frequency C: Depth gain compensation D: Demodulation E: Apodization
B: Pulse repetition frequency
To generate a sonographic image, what is the order in which the following system components are activated? A: Pulser, receiver, display, beam former, memory B: Pulser, beam former, receiver, memory, display C: Beam former, Pulser, memory, display, receiver D: Memory, beam former, Pulser, receiver, display E: Beam former, memory, Pulser, receiver, display
B: Pulser, beam former, receiver, memory, display
Bandwidth refers to: A: Number of cycles per pulse B: Range of frequencies in a pulse C: Rate of pulse repetition frequency D: Range of pulses in a frame E: Number of wavelengths in one second
B: Range of frequencies in a pulse
The unit of impedance is the: A: Joule B: Rayl C: Watt/cm2 D: Newton E: Watts/cm
B: Rayl
In this image of an artery there is a calcification with a dark vertical band extending beyond it (arrow). Which explanation best describes the etiology of the dark band? See image for question #384 A: Propagation speed error at the vessel wall interface B: Reduction in signal amplitude in tissue distal to a highly attenuating or reflecting object C: Refraction due to oblique incidence at the plaque interface D: Range ambiguity due to high PRF setting E: Comet tail artifact due to calcification in plaque
B: Reduction in signal amplitude in tissue distal to a highly attenuating or reflecting object
At low velocities, the red blood cells adhere to one another forming multicellular clumps. This is termed: A: Rayleigh scattering B: Rouleaux formation C: Huygen's principle D: Newtonian fluid E: Parabolic flow
B: Rouleaux formation
When you "freeze" the ultrasound image, where is the echo information stored? A: Transducer B: Scan converter C: Cable D: Beam former E: Receiver
B: Scan converter
In the following illustration, if the propagation speed is unchanged at the interface, which most correctly describes the sound-tissue interaction that will take place when the ultrasound wave strikes the depicted interface? See image for question #95 A: Specular reflection B: Scattering C: Diffraction D: Refraction E: None of the above
B: Scattering
Of the following, which is the best choice to help you demonstrate tissue boundaries that are not perpendicular to the sound beam? A: Speckle reducing algorithm B: Spatial compounding C: Persistence D: Panoramic imaging E: Time gain compensation
B: Spatial compounding
Which term below most correctly describes the Doppler waveform? See image for question #385 A: Aliasing B: Spectral mirroring C: Spectral broadening due to sample volume size D: Reverberation E: Bidirectional flow
B: Spectral mirroring
What control should you adjust to optimize the image if you are scanning a structure that produces very bright echoes on the display? A: Rejection B: TGC C: Edge enhancement D: Frame averaging E: Frequency
B: TGC
What system control should you adjust to compensate for sound attenuation with increasing depth? A: Dynamic range B: TGC C: Transmit power D: Overall Receiver gain E: Focus position
B: TGC
If you increase the Doppler transmit frequency, which of the following will result? A: The velocity will increase B: The Doppler frequency shift will increase C: The penetration will increase D: The frame rate will increase E: The Nyquist limit will increase
B: The Doppler frequency shift will increase
Aliasing is a potential problem in PW Doppler because of: A: The use of high pulse repetition frequencies B: The Doppler signal is sampled rather than recorded continuously C: Dynamic focusing D: The motion of the interface perpendicular to ultrasound wave propagation E: Perpendicular incidence
B: The Doppler signal is sampled rather than recorded continuously
Snell's Law describes: A: The percentage of reflection at an interface with normal incidence and different densities. B: The angle of sound transmission at an interface between media having different propagation speeds. C: The amount of attenuation of sound tissue with depth. D: The amount of Backscatter from a diffuse reflector. E: The angle of sound reflection at an interface with oblique incidence and nonspecular reflection.
B: The angle of sound transmission at an interface between media having different propagation speeds.
The Doppler frequency shift is defined as: A: The difference between the Doppler frequency and the imaging frequency B: The difference between the transmitted and received frequencies C: The time between the transmitted and received pulses D: The rate at which the transducer emits pulses E: The amplitude of the transmitted Doppler signal
B: The difference between the transmitted and received frequencies
Which of the following is associated with improper adjustment of the brightness and contrast on the video monitor? A: The spatial resolution of the resultant image will be degraded B: The operator will likely over gain or under gain the image C: The temporal resolution will be reduced D: The flicker rate of the video monitor will be increased E: The penetration of the transducer will be reduced
B: The operator will likely over gain or under gain the image
You will NOT see refraction in the sonographic image if: A: The sound beam strikes an interface at an angle of greater than 45 degrees. B: The sound beam is perpendicular to the interface. C: The sound beam is 45 degrees to the interface. D: The sound beam changes propagation speed at the interface. E: The sound beam strikes an interface at an angle of less than 45 degrees.
B: The sound beam is perpendicular to the interface
What control should you adjust to better compensate for the attenuation of sound as it propagates through tissue? A: Dynamic range B: Time gain compensation C: Acoustic power output D: Rejection E: Focusing
B: Time gain compensation
Selective reception of echoes generated within the body by nonlinear propagation describes: A: Compound imaging B: Tissue harmonic imaging C: Speckle reduction imaging D: 3D imaging E: Tomographic ultrasound imaging
B: Tissue harmonic imaging
Which imaging technique may increase visualization of the reflections from blood flow on the real-time ultrasound image? A: Compound imaging B: Tissue harmonic imaging C: 3D imaging D: Tomographic imaging E: Speckle reduction imaging
B: Tissue harmonic imaging
What is the purpose of the preamplification of the incoming signal that occurs in the transducer assembly? A: To decrease the dynamic range of the signal B: To increase echo voltages before noise is induced through the cable C: To reduce sensitivity to side lobes D: To reduce acoustic impedance mismatch between the tissue and the transducer E: To compensate for attenuation of the beam with depth
B: To increase echo voltages before noise is induced through the cable
What is the purpose of subdicing? A: To focus the beam upon transmit B: To reduce grating lobes C: To increase transmitted intensity D: To alter the transmitted frequency E: To focus the beam upon receive
B: To reduce grating lobes
For pulsed ultrasound which of the following factors determine the frequency of the sound wave? A: Pulse Repetition Frequency (PRF) B: Transmitter frequency C: Area of the transducer elements D: Pressure applied to the transducer E: All of the above
B: Transmitter frequency
The rate of sound attenuation is lowest in: A: Air B: Water C: Liver D: Bone E: Lung
B: Water
For a single transducer to offer multiple frequency selections for scanning, it must have: A: Large dynamic range B: Wide bandwidth C: Multiple rows of elements in the elevational plane D: Dynamic aperture E: Electronic steering capability
B: Wide bandwidth
Bonded to the back of the active element, it reduces the ringing of the pulse. This is commonly made of epoxy resin impregnated with tungsten filaments. When an electrical spike excites the PZT this restricts the extent of PZT deformation. The emitted sound pulse is dampened this it is short in duration and length.
Backing material
The ______ not only reduces active element vibration during transmission, but also reduces vibration during reception.
Backing material
Used to dampen the ultrasound pulse and to reduce the spatial pulse length thereby improving axial resolution.
Backing material
The range or difference between the highest and lowest frequencies in the pulse.
Bandwidth
Lateral reoslution (mm) = ________.
Beam diameter (mm)
Describes the gradual spread of the ultrasound beam in the far field.
Beam divergence
The electronics within the ultrasound system that create spike patterns is called the _______.
Beam former
Elevational resolution is determined by _______.
Beam slice thickness
A number called the _____ or the ___ describes the spread of a beam in space.
Beam uniformity coefficient SP/SA factor
Lateral resolution is dependent on ______.
Beam width
A sound pulse strikes many tissue interfaces as it propagates through soft tissue. The angle at which the wave strikes the boundary determines the _______.
Behavior of the pulse
The shorter the pulse duration, the _____ the axial resolution.
Better
In clinical situations axial resolution is ______ lateral resolution because ultrasound pulses are shorter than they are wide.
Better than
A number in scientific notation form with an exponent of zero has a value ________.
Between 1 and 10
The different measurements of intensities are important in the study of _______.
Bioeffects
The effects of the sound wave upon the biologic tissue through which it passes.
Biologic effects
B-mode stands for?
Brightness mode
A ______ may be seen on the spectral waveform in the area of post stenotic turbulence. It appears as bright echoes near the zero baseline located underneath the systolic peak.
Bruit
Related to media stiffness and helps to determine propagation speed.
Bulk modulus
Which probe would provide the best axial resolution to measure the thickness of a small structure? A: 5MHz linear array B: 7MHz linear array C: 10MHz linear array D: 5MHz curved array E: 5MHz phased array
C: 10MHz linear array
In order for distance measurements to be accurate in an ultrasound tissue phantom, the phantom sound propagation speed must be: A: 13 us/cm B: 1.54 m/s C: 154o m/s D: 1/2 the speed of sound in tissue E: Twice the speed of sound in soft tissue
C: 1540 m/s
Which of the following frequencies is considered to be ultrasound? A: 2000Hz B: 20Hz C: 2MHz D: 200 Hz E: 2Hz
C: 2MHz
The mass you are imaging has a diameter of 35mm. This value can also be expressed as: A: 350 cm B: 0.35 cm C: 3.5 cm D: 35 m E: 3.5 m
C: 3.5 cm
What 2D limitation is addressed by 3D ultrasound imaging? A: 3D provides higher frame rate B: 3D provides improved spatial resolution C: 3D provides visibility of the coronal plane D: 3D transducers are typically smaller and lighter than standard 2D transducers E: 3D imaging requires no training of the person performing the study
C: 3D provides visibility of the coronal plane
Regarding this image, the angle of the beam to the vessel is approximately: See images for question #538 A: 0 degrees B: 60 degrees C: 90 degrees D: 45 degrees E: 360 degrees
C: 90 degrees
You are scanning an interface with a high acoustic impedance mismatch. How will this be displayed on the B-mode image? A: A tall spike B: A small spike C: A bright dot D: A dark dot E: The height of the spike or brightness of the dot is not affected by acoustic impedance mismatch
C: A bright dot
In order to display a structure on your sonographic image the sound beam must be reflected at the interface. What is required for sound reflection at the interface of two structures? A: Oblique incidence at the interface boundary. B: Temperature differences between the two media. C: A difference in the acoustic impedance of the media. D: Different media diameters. E: Different attenuation coefficients.
C: A difference in the acoustic impedance of the media.
You are observing a sonographic artifact based on the interference patterns of scattered echoes. What artifact are you imaging? A: Mirror B: Grating lobe C: Acoustic speckle D: Comet tail E: Refraction
C: Acoustic speckle
Terms used to describe the strength of the sound beam include: A: Amplitude and impedance B: Amplitude and wavelength C: Amplitude and intensity D: Intensity and impedance E: Frequency and impedance
C: Amplitude and intensity
What information is present in the A-mode display? A: Frequency bandwidth, amplitude, and reflector distance B: Time, amplitude, and motion pattern C: Amplitude and reflector distance D: Time, motion pattern, reflector distance, and frequency bandwidth E: Frequency shift, amplitude, and reflector distance
C: Amplitude and reflector distance
What type of transducer has the same measurement for elevational and lateral resolution? A: Convex linear array B: Phased linear array C: Annular array D: Sequential linear array E: Mechanical sector
C: Annular array
The rapid technique used in most color Doppler systems to obtain the mean Doppler frequency shift is: A: Fast Fourier transform B: Phase quadrature C: Autocorrelation D: Zero-crossing detector E: Variance
C: Autocorrelation
Resolution of two structures at different depths along the path of the sound beam is termed: A: Contrast resolution B: Temporal resolution C: Axial resolution D: Lateral resolution E: Azimuthal resolution
C: Axial resolution
This image shows the color significantly overwriting the vessel wall. Which of the following provides the best explanation for this? See images for question #521 A: The color Doppler threshold is set too low B: The color Doppler scale is set too low C: Axial resolution is lower with color Doppler compared to B-mode D: Color Doppler uses a higher frequency transmitted pulse than B-mode E: All of the above
C: Axial resolution is lower with color Doppler compared to B-mode
What system component is most responsible for transmit focusing? A: Receiver B: Monitor C: Beam former D: Preprocessing E: System clock
C: Beam former
What color represents flow at 90 degrees to the sound beam? See images for question #532 A: Dark red B: Dark blue C: Black D: Yellow/orange E: Cyan
C: Black
What is a disadvantage of a water-path scanner? A: It reduces axial resolution B: The beam width perpendicular to the image plane is increased, resulting in poor Elevational resolution C: Bubbles in fluid can inhibit sound transmission into the body D: It useful only with very low frequencies E: The fluid path increases the mechanical index
C: Bubbles in fluid can inhibit sound transmission into the body
An M-mode display is most commonly used for what type of ultrasound imaging? A: Small parts B: Abdominal C: Cardiac D: Vascular E: Ophthalmology
C: Cardiac
You are performing a sonogram on a patient with highly attenuating tissue. Which of the following solutions would be most likely to improve penetration through the tissue? A: Decrease dynamic range B: Decrease near field TGC C: Choose a lower-frequency transducer D: Increase the scan line density E: Change the gray-scale map
C: Choose a lower-frequency transducer
You have obtained a color Doppler image of the common carotid artery. If the received ultrasound frequency is greater than the transmitted ultrasound frequency, which of the following would be correct? A: Color encoding red, negative Doppler shift B: Color encoding blue, negative Doppler shift C: Color encoding red, positive Doppler shift D: Color encoding blue, positive Doppler shift E: No Doppler shift was detected
C: Color encoding red, positive Doppler shift
What action below would be most in keeping with the ALARA principle while performing a diagnostic ultrasound examination? A: Allow multiple students to scan an obstetrical patient because the fetus is in a good position for imaging. B: Prolong the sonogram to make videos of the fetus for each family member. C: Complete the diagnostic scan in a timely fashion at the lowest output power that achieves a quality image. D: Maximize the acoustic output to brighten the overall image. E: Extend the sonogram beyond the intended scope of the exam requisition.
C: Complete the diagnostic scan in a timely fashion at the lowest output power that achieves a quality image.
What receiver function is responsible for decreasing the difference between the smallest and largest received signal amplitudes? A: Amplification B: Compensation C: Compression D: Demodulation E: Rejection
C: Compression
Which of the following describes an analog signal? A: Discrete values B: Fixed steps between values C: Continuous variation of the signal is possible D: Levels are determined by bits E: No analog signals exist in modern instruments
C: Continuous variation of the signal is possible
What type of Doppler device uses two elements, one to receive and one to transmit? A: Power Doppler B: Color Doppler C: Continuous-wave Doppler D: Pulsed-wave Doppler E: All of the above
C: Continuous-wave Doppler
What can you improve by changing gray-scale map? A: Axial resolution B: Lateral resolution C: Contrast resolution D: Elevational resolution E: Temporal resolution
C: Contrast resolution
Relative measurement of intensity based on a logarithmic scale is expressed in: A: Newtons per cm squared B: Watts per cm squared C: Decibels D: Pascals E: Neper
C: Decibels
While performing a color Doppler exam in the abdomen you have adjusted several system controls and notice that the frame rate has decreased. Which of the following adjustments can you make to improve the color frame rate? A: Increase the packet size B: Decrease the pulse repetition frequency C: Decrease the color box width D: Increase the scan line density E: Increase the wall filter
C: Decrease the color box width
While performing an obstetrical sonogram, you wish to increase the frame rate to evaluate the fetal heart. What should you do? A: Increase scan line density B: Increase the number of focal zones C: Decrease the sector width D: Decrease the system pulse repetition frequency E: All of the above
C: Decrease the sector width
What effect will you detect in the image if you increase the threshold control? A: Increased image brightness B: Decreased image brightness C: Decreased appearance of weak echo signals D: Increased appearance of strong echo signals E: Decreased appearance of strong echo signals
C: Decreased appearance of weak echo signals
You have increased the packet size while using color Doppler to evaluate flow. What negative result will occur from this action? A: Decreased penetration B: Decreased flow sensitivity C: Decreased frame rate D: Increased variance E: Increased spectral broadening
C: Decreased frame rate
If you choose a lower-frequency transducer to image a highly attenuating structure, what trade off are you making? A: Decreased penetration for increased resolution. B: Decreased beam intensity for longer wavelengths. C: Decreased spatial resolution for improved penetration. D: Increased beam refraction for higher sound speed. E: Increased round-trip travel time for improved resolution.
C: Decreased spatial resolution for improved penetration.
What receiver function listed below is NOT operator-adjustable? A: Amplification B: Compensation C: Demodulation D: Rejection E: A and D
C: Demodulation
Ultrasound propagation velocity depends on: A: Amplitude and frequency B: Impedance and attenuation C: Density and compressibility D: Dynamic range and compression E: Impedance and density
C: Density and compressibility
What determines acoustic impedance? A: Frequency and propagation speed B: Frequency and interface size C: Density and propagation speed of the medium D: Angle of incidence and media propagation speed E: Frequency and media density
C: Density and propagation speed of the medium
Which phenomenon is associated with a pattern produced by a sound beam after passing through a small aperture? A: Scattering B: Absorption C: Diffraction D: Interference E: Diffuse reflection
C: Diffraction
String test objects are used to evaluate: A: Contrast resolution B: Axial resolution C: Doppler accuracy D: Elevation resolution E: Lateral resolution
C: Doppler accuracy
What information is colorized in an image using power Doppler? A: Frequency shift B: Flow velocity C: Doppler signal amplitude D: Frequency bandwidth E: Acoustic power
C: Doppler signal amplitude
Which is an assumption of sonographic imaging that determines how detected echoes are mapped in the image? A: Sound waves travel along curved paths B: Velocity is a constant 333 m/s C: Echoes originate from the most recently transmitted pulse D: Large structures yield a high brightness level on the display E: Media with varying propagation speeds alter the travel time of the sound pulse
C: Echoes originate from the most recently transmitted pulse
What best describes the method used to create the triangular-shaped image format in the image above? See image for question #247 A: Mechanical steering B: Electronic steering with elements fired in small groups C: Electronic steering with most elements fired for each pulse-echo sequence. Small time differences steer the beam. D: Curved lens E: Mirror
C: Electronic steering with most elements fired for each pulse-echo sequence. Small time differences steer the beam.
In this illustration, letter B is demonstrating what type of resolution? See image for question #426 A: Axial B: Lateral C: Elevation D: Contrast E: Temporal
C: Elevation
Which statement is most accurate regarding resolution with a standard one dimensional linear array transducer? A: Axial resolution is the worst measure of resolution with this type of transducer. B: Lateral resolution is the worst measure of resolution with this type of transducer. C: Elevational resolution is the worst measure of resolution with this type of transducer. D: Isotropic spatial resolution is achieved. E: Temporal resolution is the worst measure if resolution with this type of transducer.
C: Elevational resolution is the worst measure of resolution with this type of transducer.
What should you limit when the thermal index exceeds 1? A: Overall gain B: TGC C: Exposure time D: Scanning depth E: All of the above
C: Exposure time
What advantage is related to the transducer type in question #257? (Tightly curved array) A: Axial resolution is improved B: Lateral resolution is improved C: Field of view is improved D: Temporal resolution is improved E: Elevation resolution is improved
C: Field of view is improved
Where is the point of maximum intensity in a sound beam? A: Curie point B: Fresnel zone C: Focal point D: Fraunhofer zone E: F number
C: Focal point
You are using a linear array transducer with 4 transmit focal zones. How many pulses are required on each scan line to create the image? A: One B: Two C: Four D: Six E: Eight
C: Four
The number of images displayed per second in real-time imaging is termed the: A: Pulse repetition frequency B: Pulse repetition period C: Frame rate D: Pulse duration E: Pulse length
C: Frame rate
Increasing which of the following will result in improved axial resolution? A: Pulse duration B: Pulse length C: Frequency D: Period E: Focusing
C: Frequency
What two controls affect the spatial resolution of the color image? A: Line density and ensemble length B: Ensemble length and priority C: Frequency and line density D: Frequency and ensemble length E: Priority and frequency
C: Frequency and line density
Which of the following best describes the Doppler frequency shift when you encounter high velocities within a vessel? A: Amplitude is increased B: Power is increased C: Frequency shift is increased D: Bandwidth is decreased E: All of the above
C: Frequency shift is increased
What Doppler control should be adjusted to optimize this Doppler spectral waveform? See image for question #474 A: Wall filter B: Packet size C: Gain D: Pulse repetition frequency E: Baseline
C: Gain
While performing a sonographic examination, you have performed both preprocessing and postprocessing functions. Which of the following functions is postprocessing? A: Write-zoom B: Frequency change C: Gray-scale map assignment D: Scan line density E: Acoustic power output
C: Gray-scale map assignment
When you switch from a 2.5 MHz to a 5 MHz transducer the sound wavelength: A: Doubles B: Quadruples C: Halves D: Quarters E: Is unaffected
C: Halves
A nosocomial infection is defined as one that is: A: Resistant to antibiotics B: Restricted to the respiratory system C: Hospital-acquired D: Not contagious E: Requires isolation
C: Hospital-acquired
A digital scan converter is another name for what system component? A: Pulser B: Receiver C: Image memory D: Analog to digital converter E: Beam former
C: Image memory
During the course of a sonographic exam, you notice lateral splaying of the echoes in the far field. What can you do to improve the image? A: Use the maximum acoustic power. B: Use the lowest line density setting. C: Increase the number of transmit focal zones and optimize their location. D: Decrease the scanning depth. E: Increase the sector width.
C: Increase the number of transmit focal zones and optimize their location.
Color flash artifact is obscuring the anatomy of interest in an exam of the abdominal aorta. What can you do to reduce impact of the flash? A: Increase the color gain B: Decrease the pulse repetition frequency C: Increase the wall filter D: Increase the packet size E: Increase the Doppler transmit frequency
C: Increase the wall filter
What would be the most likely result from lowering the color threshold? A: Increased visibility of small vessel flow in a parenchymal organ B: Decreased flash artifact C: Increased color writing on the vessel or cardiac wall D: Increased frame rate E: Improved color penetration
C: Increased color writing on the vessel or cardiac wall
You made changes to the following controls during a sonogram. Which adjustment increased the duty factor? A: Increasing receiver gain B: Increasing output power C: Increasing pulse repetition frequency D: Increasing scanning time E: Increasing time gain compensation
C: Increasing pulse repetition frequency
Which of the following adjustments would NOT decrease frame rate? A: Increasing the number of transmit focal zones B: Increasing scanning depth C: Increasing the receiver gain D: Increasing scan line density E: Increasing sector width
C: Increasing the receiver gain
Power divided by the beam area is equal to the: A: Probe angle B: Speed of sound C: Intensity D: Attenuation E: Amplitude
C: Intensity
The layer of the vessel wall that is a single layer of cells backed by a thin layer of elastin and collagen fibers is: A: Adventitia B: Media C: Intima D: Internal elastic Lamina E: External elastic Lamina
C: Intima
Loss of fluid energy through inertia: A: Is greatest during steady flow through a rigid tube of constant caliber B: Is best described as Poiseuille's law C: Is greatest in a tortuous vessel with multiple obstructions D: Accounts for less energy loss than viscous losses E: Is greatest with high flow speeds in a large tube
C: Is greatest in a tortuous vessel with multiple obstructions
Parabolic flow is most likely to occur with: A: Distal to a stenosis B: Small veins C: Laminar flow states D: Disturbed flow states E: When aliasing is present
C: Laminar flow states
You have obtained an ultrasound image that demonstrates refraction of the sound beam. The artifact might be manifested as: A: Axial displacement of a reflector B: Enhancement distal to a reflector C: Lateral displacement of the displayed position of a reflector D: Multiple images of a single reflector E: Increased brightness of a reflector
C: Lateral displacement of the displayed position of a reflector
A commonly used material in modern transducer elements is: A: Tungsten powder and epoxy resin B: Quartz C: Lead zirconate titanate D: Rubber E: None of the above
C: Lead zirconate titanate
The graphic overlay on this phantom image represents a gray-scale assignment curve. What type of curve is being used? See image for question #573 A: S-curve B: Root curve C: Linear curve D: Light curve E: None of the above
C: Linear curve
Which of the following is NOT associated with a low Q transducer? A: Wide bandwidth B: Multifrequency selection C: Long pulse length D: Diagnostic pulse-wave ultrasound E: Loss of most energy in first few vibrations
C: Long pulse length
Wavelength is measured in: A: Hertz B: Microseconds C: Millimeters D: Rayls E: Newtons
C: Millimeters
Which of the following artifacts may result in both an axial and lateral displacement of a reflector on the ultrasound image? A: Refraction B: Side lobe C: Multipath reflections D: Partial volume E: Enhancement
C: Multipath reflections
For a nonfocused transducer, the region between the transducer element and the point at which the sound beam is narrowest is called the: A: Far field B: Fraunhofer zone C: Near zone length D: Focal distance E: Both A and B
C: Near zone length
When you change the transmit frequency which of the following is altered? A: Displacement amplitude of the particles in the medium. B: Speed at which the sound wave propagates through the medium. C: Number of cycles per second. D: Pulses transmitted per second. E: Number of electrical impulses applied to the transducer per second.
C: Number of cycles per second.
You are performing a 3D sonogram and notice the volume rate is 8 Hz. What does this represent? A: Number of transmitted sound pulses per second B: Number of received pulses per minute C: Number of volumes displayed per second D: Number of frames per volume E: Number of frames per second
C: Number of volumes displayed per second
What two conditions must be present to cause refraction of a sound wave? A: Perpendicular incidence and identical media propagation speeds. B: Perpendicular incidence and reflector size smaller than one wavelength. C: Oblique incidence and different media propagation speeds. D: Oblique incidence and reflector size smaller than one wavelength. E: Normal incidence and reflector size smaller than one wavelength.
C: Oblique incidence and different media propagation speeds.
While performing a sonogram, you encounter the following interfaces. Which will produce the weakest reflected signal? A: Organ parenchyma/fluid B: Organ parenchyma/air C: Organ parenchyma/organ parenchyma D: Organ parenchyma/bone E: Organ parenchyma/ligament
C: Organ parenchyma/organ parenchyma
Which control would you adjust to increase the intensity of the transmitted pulse? A: Receiver gain B: Depth of scanning C: Output power D: Time gain compensation E: Dynamic range
C: Output power
A commonly used process for determining direction in a Doppler instrument is: A: Zero-crossing detection B: Autocorrelation C: Phase quadrature detection D: Range gating E: Spectral analysis
C: Phase quadrature detection
Axial resolution is chiefly determined by: A: Beam width B: Transducer diameter C: Pulse duration D: Line density E: Frame rate
C: Pulse duration
Axial resolution is determined chiefly by: A: Beam width B: Transducer diameter C: Pulse duration D: Attenuation coefficient E: Intensity
C: Pulse duration
When scanning with pulsed-wave Doppler you would affect the acoustic exposure by changing which of the following? A: Doppler gain B: High pass filter C: Pulse repetition frequency D: Baseline position E: Doppler angle
C: Pulse repetition frequency
When you increase the scanning depth, which of the following is automatically decreased by the system to avoid range ambiguity? A: Number of focal zones B: Sector width C: Pulse repetition frequency D: Pulse repetition period E: Pulse duration
C: Pulse repetition frequency
If you increase pulse repetition frequency to a level too great for the depth of field, the result will be: A: Increased side lobes B: Increased grating lobes C: Range ambiguity D: Decreased frame rate E: Increased electronic noise
C: Range ambiguity
The regions of low pressure and density that are formed during sound propagation are termed: A: Compressions B: Shear waves C: Rarefactions D: Cavitation E: Bulk modulus
C: Rarefactions
The Doppler frequency shift is the difference between the: A: Transmitted frequency and the pulse repetition frequency B: Received frequency and the pulse repetition frequency C: Received frequency and the transmitted frequency D: Frequency bandwidth and the pulse repetition frequency E: Pulse repetition frequency and the pulse length
C: Received frequency and the transmitted frequency
What receiver function converts the negative portion of the Radiofrequency (RF) signal to positive? A: Compression B: Demodulation C: Rectification D: Enveloping E: Amplification
C: Rectification
Which of the following is an example of a Rayleigh scatterer? A: Renal capsule B: Arterial wall C: Red blood cell D: Bowel gas E: Femur
C: Red blood cell
Dynamic Apodization is a method employed to: A: Focus the beam at multiple depths on transmit. B: Focus the beam at multiple depths on receive. C: Reduce side lobes. D: Reduce beam width in the z-axis. E: Steer the beam.
C: Reduce side lobes.
The matching layer between the piezoelectric element and the tissue is designed to: A: Insulate the patient from the hot element. B: Reduce the vibration of the transducer. C: Reduce the acoustic impedance mismatch between the element and tissue. D: Increase the reflection coefficient at the transducer-skin interface. E: Decrease spatial pulse length.
C: Reduce the acoustic impedance mismatch between the element and tissue.
You are imaging a fluid-filled structure that has equidistant horizontal bands appearing in the near field. The bands have decreasing brightness with depth. What artifact are you imaging? A: Slice thickness B: Side lobes C: Reverberation D: Comet tail E: Ring down
C: Reverberation
Which of the following actions is NOT compliant with HIPAA? A: Cropping all patient identifiers from images used for teaching purposes. B: Refraining from disclosing patient health information without proper authorization. C: Reviewing your neighbors medical studies on your hospital PACS system so you can give her your opinion of her condition. D: Covering your daily requisition list so that the names are not visible to patients and visitors. E: All of these actions are compliant with HIPAA.
C: Reviewing your neighbors medical studies on your hospital PACS system so you can give her your opinion of her condition.
The range equation describes the relationship between: A: Acoustic impedance of two media B: Side lobe intensity between two crystals C: Round-trip pulse travel time and distance to the reflector D: Bandwidth and transducer frequency E: All of the above
C: Round-trip pulse travel time and distance to the reflector
The Nyquist limit describes which of the following? A: Penetration limit of pulsed-wave Doppler B: Transmit time of pulsed-wave Doppler C: Sampling frequency needed for detecting the Doppler signal unambiguously D: Sampling method used for continuous-wave Doppler E: Method used for determining directional information in a Doppler-shifted signal
C: Sampling frequency needed for detecting the Doppler signal unambiguously
During a sonographic exam, you adjusted the following controls. Which one was most likely to have affected the frame rate? A: Amplification B: Transmit power C: Scan depth D: Time gain compensation E: Compression
C: Scan depth
What can you do to enhance the visibility of a specular reflector? A: Scan with the lowest possible frequency. B: Scan with oblique incidence. C: Scan with perpendicular incidence. D: Increase the distance to the reflector. E: Scan with an incident angle of 45 degrees.
C: Scan with perpendicular incidence.
You are imaging a structure that is highly attenuating. Which imaging effect do you expect to encounter? A: Enhancement B: Increased penetration C: Shadowing D: Refraction E: Increased acoustic speckle
C: Shadowing
This phantom is used to detect: See image for question #595 A: Lateral resolution B: Axial resolution C: Slice thickness D: Dead zone E: Contrast resolution
C: Slice thickness
What is a side lobe? A: Uneven transducer element B: Accessory pulse used for electronic steering C: Sound beam emitted from the transducer that travels in a different direction from the main beam D: Nonlinear propagation of the sound beam E: Additional backing material on the transducer edge used to reduce lateral vibrations
C: Sound beam emitted from the transducer that travels in a different direction from the main beam
What type of resolution is determined by the number of pixels in the scan converter? A: Temporal B: Contrast C: Spatial D: Elevational E: All of the above
C: Spatial
What defines the best axial resolution that can be obtained with a given transducer? A: Spatial pulse length x 2 B: Spatial pulse length x 4 C: Spatial pulse length / 2 D: Spatial pulse length / 4 E: Equal to the spatial pulse length
C: Spatial pulse length / 2
When you image sound reflected from a large, smooth interface, you are observing results of: A: Rayleigh scattering B: Diffraction C: Specular reflection D:Diffusion E: Refraction
C: Specular reflection
An echo from which one of the following sound reflectors is most dependent on the angle of incidence? A: Rayleigh scatterer B: Diffuse reflector C: Specular reflector D: Acoustic scatterer E: Nonspecular reflector
C: Specular reflector
As a general observation about media in diagnostic sonography sound propagates faster in materials with greater: A: Compressibility B: Acoustic impedance C: Stiffness D: Refractive index E: All of the above
C: Stiffness
Pulsing of the transmitted sound wave is necessary for real-time imaging because: A: The transducer becomes too hot to handle if continuous waves are emitted B: The crystal in the transducer will break under the stress of continuous emissions C: The depth of the interface from which the echo originated can be determined D: Lateral resolution is improved by pulsed transmission E: Temporal resolution is improved by pulsed transmission
C: The depth of the interface from which the echo originated can be determined
The incoming raw echo signals must be compressed into a smaller dynamic range because: A: A wide dynamic range results in increased display of electronic noise B: A wide dynamic range does not allow differentiation between echoes arriving from different depths C: The display cannot accommodate the wide dynamic range of the incoming signals D: The existing wide dynamic range significantly slows the frame rate E: A wide dynamic range compromises spatial resolution
C: The display cannot accommodate the wide dynamic range of the incoming signals
Atherosclerosis begins within: A: The adventitia B: The media C: The intime D: Both A and B E: All of the above
C: The intime
When you adjust the pulse repetition frequency, you are changing: A: The number of pulses per line. B: The number of pulses per frame. C: The number of pulses per second. D: The number of wavelengths per second. E: The number of wavelengths per pulse.
C: The number of pulses per second.
If the number of cycles in a pulse is increased but the wavelength remains the same, which of the following is true? A: The frequency is increased. B: The propagation speed is increased. C: The pulse duration is increased. D: The period is decreased. E: The bulk modulus is decreased.
C: The pulse duration is increased.
The term signal-to-noise ratio denotes: A: The ratio of the electronic noise to the Radiofrequency noise B: The ratio of the system power to the weakest detectable signal C: The relative amplitude of the signal compared to the amplitude of the noise D: The ratio of the largest to the smallest signal that the system can display E: The ratio of the transducer frequency to the received echo intensity
C: The relative amplitude of the signal compared to the amplitude of the noise
You are using a conventional linear array transducer to image the phantom in the previous question. Why does the tube labeled "B" contain echoes, whereas the tube labeled "A" does not? See image for question #575 A: Since axial resolution decreases with depth, artifactual echoes are displayed from above and below the tube B: The frame rate was too slow to display the deeper tube accurately C: The slice thickness at the level of tube B was wider than at tube A D: The electronic focusing at the level of tube A is more powerful than at the level of tube B E: The dynamic receive focusing cannot work at the depth of the tube B
C: The slice thickness at the level of tube B was wider than at tube A
The interpreting physician has asked you to use a stand-off pad to evaluate a superficial mass. What is the main advantage the stand-off pad provides to improve the image? A: The stand-off pad has an acoustic impedance closer to that of the crystal which results in improved transmission of sound into the body. B: The stand-off pad has a propagation speed equal to twice that of soft tissue, which decreases the wavelength of the sound beam. C: The stand-off pad increases the distance between the transducer and the mass, making it more likely that the mass will be located close to the elevational focus of the sound beam. D: The stand-off pad creates a soft interface between the crystal and the tissue, increasing constructive interference and reducing scattering. E: The stand-off pad eliminates artifacts associated with reverberation, side lobes, and grating lobes.
C: The stand-off pad increases the distance between the transducer and the mass, making it more likely that the mass will be located close to the elevational focus of the sound beam.
Electronic focusing in the transmit mode is accomplished using: A: Curved crystal elements B: Changeable lens C: Time delays to excite transducer elements D: High pulse repetition frequency E: Receive time delays
C: Time delays to excite transducer elements
What system control do you adjust to equalize the difference in echo amplitudes received from similar structures situated at different depths? A: Dynamic range or compression B: Rectification C: Time gain compensation D: Pulse repetition frequency E: Rejection
C: Time gain compensation
What is the purpose of the gel coupling between the transducer and the skin? A: To reduce heating of the epidermis caused by sound absorption and friction. B: To soften the skin and soothe the patient. C: To provide a medium for sound transmission since ultrasound does not propagate through air. D: To reduce the impedance differences between the transducer and the skin. E: To lessen refraction of the sound at the skin surface and improve sound transmission.
C: To provide a medium for sound transmission since ultrasound does not propagate through air.
If you wish to improve border definition, what imaging enhancement should you use? A: Use a lower line density B: Use a 2D array transducer C: Use spatial compound imaging D: Apply a speckle reduction algorithm E: Use frame averaging
C: Use spatial compound imaging
To practice the ALARA principle which of the following techniques should you employ? A: Always use the least amount of Reciever gain that allows adequate tissue visualization. B: Adjust the controls so that the MI and TI read outs exceed 1. C: Use the lowest transmit power that allows adequate tissue visualization. D: Use the highest frame averaging setting. E: Maximize exposure time.
C: Use the lowest transmit power that allows adequate tissue visualization.
The length of space over which one cycle occurs is known as the: A: Duty factor B: Spatial pulse length C: Wavelength D: Pulse repetition frequency E: Pulse duration
C: Wavelength
The Frank-Starling mechanism helps to explain that when an arrhythmia is present, the peak systolic velocity following a heart cycle with a longer time interval _______ to one with a shorter time interval. A: Will be equal B: Will be lower than C: Will be higher than D: Will be unrelated E: Will be lower than but unpredictable
C: Will be higher than
A DICOM feature that allows you to select a patient name and have it automatically populate the patient information on the ultrasound system is: A: VPN B: PRN C: Worklist D: JAVA E: HIPAA
C: Worklist
Continuous wave sound ______ create anatomic images.
Cannot
Variance maps are primarily used for _____ scanning.
Cardiac
The cylindrical tube constructed of metal or plastic that protects the internal components of the transducer from damage and also insulates the patient from electrical shock.
Case
What are the units of the half-value layer?
Centimeters
Acoustic impedance is also called _______.
Characteristic impedance
A method of displaying the average Doppler frequency shifts.
Color Doppler
Color Doppler is also called?
Color flow imaging
In color Doppler, the frequency shift is _______.
Color-encoded
Commonly seen with metallic objects and multiple reverberations within a highly reflective object cause the artifact.
Comet tail artifact
High-pressure regions are _____.
Compressions
At the boundary between 2 media the principle of ______ applies.
Conservation of energy
Occurs when the resulting wave is larger than either of its components.
Constructive interference
The interference of a pair of in-phase waves results in the formation of a single wave of greater amplitude than either of its components. This combination is called ______.
Constructive interference
The delay patterns during receive-focusing changes ______ as the transducer listens for reflections.
Continuously
A transducer is any device that ______.
Converts one form of energy into another
An array transducer where the active elements are arranged in a bowed or arched line. The transducer may also be called a curved or curvilinear array.
Convex array
What is another name for parallel processing?
Coprocessing
With convex arrays, the transcode face is ______.
Curved
The shape corresponding to the image created by a phased array transducer most closely corresponds to which of the following? See image for question #230 and 231 A B C D E
D
The sound propagation speed used to calibrate range-measuring circuits on diagnostic sonography instruments is: A: 1.54m/s B: 1560mm/s C: 1.46mm/us D: 1540m/s E: 146,000cm/s
D: 1,540m/s
You have been asked to perform an ultrasound study of a structure located about 3cm below the skin surface. Which transducer frequency range would be most appropriate for this study? A: 2-5 MHz B: 4-8 MHz C: 8-10 MHz D: 10-12 MHz E: 5 MHz
D: 10-12 MHz
While performing a Doppler ultrasound examination you adjust the pulse repetition frequency to 12 kHz. This can also be expressed as: A: 0.12 Hz B: 1200 Hz C: 1.2 MHz D: 12,000 Hz E: 120 MHz
D: 12,000 Hz
In the image below, how many transmit focal zones are being used? See image for question #245 A: The number of transmit focal zones is not indicated B: 1 C: 2 D: 3 E: 4
D: 3
What is the velocity of an ultrasound wave in a bone? A: 333m/s B: 8050m/s C: 1540m/s D: 4080m/s E: 1240m/s
D: 4080m/s
Doppler pulses used for diagnostic purposes are typically ______ cycles long: A: 0-2 B: 2-3 C: 4-5 D: 6-20 E: Greater than 100
D: 6-20
You measured an area reduction of 90% in the artery shown on the following page. This is equal to a diameter reduction of: See image for question #498 A: 25% B: 30% C: 50% D: 75% E: 90%
D: 75%
Acoustic impedance increases with which of the following? A: Increased tissue density B: Increased propagation speed C: Increased transducer frequency D: A and B E: All of the above
D: A and B
When color Doppler is activated, in order to maintain frame rate, what may be reduced in the underlying B-mode image? A: The number of focal zones B: The scan line density C: The frame averaging D: A and B E: B and C
D: A and B
Preprocessing functions may be defined as: A: Any function that can be performed on a frozen image B: A function that takes place in the beam-former and is not controllable by the operator C: A function that allows increased focusing of the sound beam D: A function that is performed before the echo data are stored in memory E: Any function that changes the quality of the ultrasound image
D: A function that is performed before the echo data are stored in memory
Without interpolation, which of the following would best describe the resultant B-mode image? A: Very weak echoes in the far field compared to the near field B: Poor differentiation between the ultrasound signal and the noise floor C: Saturation of the white shades on the ultrasound monitor D: A series of scan lines with blank data between the lines E: A bistable image
D: A series of scan lines with blank data between the lines
During a diagnostic ultrasound examination, you encounter all of the interactions of ultrasound and tissue listed below. Which one will NOT cause a redirection of part of the ultrasound energy? A: Reflection B: Scattering C: Divergence D: Absorption E: Refraction
D: Absorption
The transfer of acoustic energy into heat is termed: A: Scattering B: Diffusion C: Diffraction D: Absorption E: Refraction
D: Absorption
What artifact will you see in the color Doppler image if you cannot increase the PRF to a level greater than 2 times than that of the Doppler frequency shift? A: Range ambiguity B: Overestimation of the flow velocity C: Overestimation of the Doppler frequency shift D: Aliasing E: All of the above
D: Aliasing
What can you do to achieve a higher frame rate? A: Decrease the number of focal zones B: Decrease the line density C: Decrease the sector width D: All of the above E: None of the above
D: All of the above
What information does the z-axis (brightness) on the Doppler spectrum provide? A: Velocity B: Velocity range C: Bandwidth D: Amplitude E: Frequency shift
D: Amplitude
With an A-mode display, the internal contents of a simple cyst will appear as: A: An area with very dark shades of gray B: An area with rapidly moving spikes C: An area with tall spikes surrounded on each end with areas absent of spikes D: An area with no spikes E: An area with multiple tiny spikes
D: An area with no spikes
What type of resolution is affected most by pulse duration? A: Lateral resolution B: Contrast resolution C:Temporal resolution D: Axial resolution E: Elevational resolution
D: Axial resolution
What component of a pulsed-wave transducer helps to reduce the spatial pulse length and improve axial resolution? A: Matching layer B: Lens C: Element D: Backing material E: Radiofrequency shield
D: Backing material
Decreased pressure occurs in areas of high flow speeds. This is known as the: A: Continuity rule B: Reynolds number C: Poiseuille's law D: Bernoulli effect E: Nyquist limit
D: Bernoulli effect
Digital to analog conversion of the ultrasound signal must occur at what part of the imaging process? A: Between the transducer and the receiver B: Between the beam former and the transducer C: Between the receiver and the scan converter D: Between the scan converter and the display E: Digital to analog conversion does not occur in the ultrasound system
D: Between the scan converter and the display
You are performing a sonogram and notice that the thermal index (TI) is greater than 1. Any increase in temperature would be greatest in: A: Liver B: Lung C: Kidney D: Bone E: Bladder
D: Bone
A group of 8 bits is called: A: Binary B: Kilobyte C: Pixel D: Byte E: Matrix
D: Byte
During production of a sonogram you image the following structures. Which is the MOST attenuating? A: Blood B: Bile C: Soft tissue D: Calcification E: Muscle
D: Calcification
Which of the following would be most helpful to enhance the contrast difference between tissues having subtle variations in echogenicity? A: Decreasing the acoustic power output B: Decreasing the scan line density C: Performing a read-zoom over the area of interest D: Changing the gray-scale map assignment E: Increasing the overall receiver gain
D: Changing the gray-scale map assignment
In an ultrasound phantom, the targets typically used for measuring axial resolution are: A: Multiple round fluid-filled structures B: Multiple round Hyperechoic simulated lesions C: Multiple equidistant rods D: Closely spaced targets of varying distances E: Long fluid-filled tubes
D: Closely spaced targets of varying distances
What control should you adjust to modify the image if the attenuation coefficient of the tissue is very high? A: Dynamic range B: Rejection C: Threshold D: Compensation E: Compression
D: Compensation
What Doppler technique does NOT provide range resolution? A: Color Doppler B: Power Doppler C: Pulsed-wave Doppler D: Continuous-wave Doppler E: No Doppler technique can provide range resolution
D: Continuous-wave Doppler
The transducer lens, which may be easily damaged by mechanical shock, is represented by letter: See image for question #586 A: A B: B C: C D: D E: E
D: D
You obtained this color Doppler image during a hepatic sonogram. There is no color signal detected within the portal vein. What can you do to improve sensitivity to slow flow? See images for question #453 A: Increase wall filter B: Decrease packet size C: Decrease color gain D: Decrease pulse repetition frequency E: Change color map
D: Decrease pulse repetition frequency
What can you do to improve the temporal resolution while scanning? A: Increase the number of focal zones B: Increase the depth C: Increase the sector width D: Decrease the acoustic scan line density E: Decrease the acoustic power output
D: Decrease the acoustic scan line density
You expanded the image sector width to improve visualization of a large mass. What can you do to maintain the same temporal resolution you had before your adjustment? A: Increase the digitization bit depth B: Increase the number of scan lines C: Decrease the number of pixels in the image matrix D: Decrease the number of focal zones E: Decrease the pulse repetition frequency
D: Decrease the number of focal zones
What function of the receiver converts electrical signals from Radiofrequency to video form? A: Amplification B: Compensation C: Compression D: Demodulation E: Rejection
D: Demodulation
For soft tissue one of the factors responsible for determining acoustic impedance is: A: Attenuation B: Frequency C: Absorption D: Density E: Amplitude
D: Density
Which of the following best describes M-mode? A: Presentation of reflector amplitudes along multiple lines of sight B: Two-dimensional gray-scale image C: Movement of a single structure along multiple lines of sight D: Depth of reflectors along a single line of sight vs. time E: Frequency shift of moving reflectors along a single line of sight
D: Depth of reflectors along a single line of sight vs. time
If you increased the Doppler transmit frequency during a Doppler exam, what would be the expected result? A: Penetration would increase B: Aliasing would be reduced C: Flow velocity would increase D: Doppler frequency shift would increase E: All of the above
D: Doppler frequency shift would increase
Which of the following is NOT a function of the receiver? A: Amplification B: RF to video conversion C: Demodulation D: Dynamic aperture E: Compression
D: Dynamic aperture
The ratio of the largest to the smallest signal that a system can handle is termed: A: Apodization B: Compression C: Threshold D: Dynamic range E: Pulse repetition frequency
D: Dynamic range
How is the reflector depth determined with pulse-echo ultrasound? A: Echo amplitude B: Echo dynamic range C: Echo frequency D: Echo arrival time E: Echo phase
D: Echo arrival time
In this phantom image, two fluid-filled tubes are present. What type of resolution is being evaluated? See image for question #575 A: Axial B: Lateral C: Contrast D: Elevational E: Temporal
D: Elevational
You are scanning a phantom containing multiple rows of identical 5mm spherical fluid structures embedded in a tissue-mimicking material. What type of resolution is best evaluated with this phantom? A: Axial B: Lateral C: Contrast D: Elevational E: Temporal
D: Elevational
Acoustic impedance: A: Is independent of the speed of sound B: Is inversely proportional to the density C: Is greater in gas than in metal D: Equals density times the propagation speed E: Is independent of the density
D: Equals density times the propagation speed
In the scan converter, interpolation is performed to: A: Amplify the reflected signal in comparison to the background noise B: Decrease the dynamic range to a level that can be handled by the monitor C: Amplify weak echo signals from deep structures to compensate for beam attenuation D: Fill in the empty pixels that occur between scan lines E: Increase the number of shades of gray in the resultant image
D: Fill in the empty pixels that occur between scan lines
Which of the following factors does NOT affect impedance? A: Stiffness B: Density C: Propagation speed D: Frequency E: All of the above affect impedance.
D: Frequency
Wavelength depends on what two factors? A: Frequency and amplitude. B: Amplitude and propagation speed. C: Period and frequency. D: Frequency and propagation speed. E: Amplitude and intensity.
D: Frequency and propagation speed.
When you select harmonic imaging, which artifact is less likely to be observed? A: Refraction B: Shadowing C: Ring-down D: Grating lobes E: Speed of sound
D: Grating lobes
If you are using a transducer with poor elevation resolution, which of the following problems are you most likely to encounter? A: Inability to resolve two structures that lie close together and parallel to the path of the beam B: Inability to resolve two structures that lie close together, perpendicular to the path of the beam, and parallel to the long axis of the transducer C: Inability to penetrate through dense tissue D: Inability to clearly demonstrate small cystic structures E: Inability to demonstrate rapidly moving structures accurately
D: Inability to clearly demonstrate small cystic structures
Imaging frame rate decrease when you: A: Decrease frequency B: Increase dynamic range C: Increase frame averaging D: Increase sector width E: Decrease the number of transmit focal zones
D: Increase sector width
A waveform from the internal carotid artery obtained at a Doppler angle of 45 degrees shows aliasing. Which of the following choices will help you unwrap this waveform? A: Decrease the angle of incidence B: Decrease the high pass filter C: Raise the zero baseline D: Increase the pulse repetition frequency E: Increase the Doppler frequency
D: Increase the pulse repetition frequency
During performance of an obstetrical ultrasound exam you adjust the system parameters to improve the image. Which of the following parameters would increase acoustic exposure? A: Increase gain B: Increase TGC C: Increase frequency D: Increase transmit power E: Increase frame averaging
D: Increase transmit power
The dark area indicated by the arrow in this image is primarily due to: See image for question #146. A: Beam refraction B: Beam enhancement C: Destructive interference D: Increased attenuation E: All of the above
D: Increased attenuation
You have increased the output power by 10 dB. The signal intensity has: A: Doubled B: Tripled C: Quadrupled D: Increased by a factor of 10 E: Increased by a factor of 100
D: Increased by a factor of 10
The image on the left demonstrates poor lateral resolution compared to the image on the right. How were the system controls adjusted to optimize the image on the right? See image for question #207 A: Increased dynamic range B: Decreased transducer frequency C: Changed gray map D: Increased line density E: Reduced frame averaging
D: Increased line density
Which of the following is most likely also to decrease beam intensity? A: Increasing acoustic output B: Decreasing receiver gain C: Increasing focusing D: Increasing beam area E: Increasing amplitude
D: Increasing beam area
What is the purpose of the Radiofrequency shield that is placed around the crystal and backing material of the ultrasound probe? A: It helps to transmit radio waves into the body. B: It aids transmission of the electric signal to the crystal. C: It reduces the incoming electric signal strength from the body. D: It reduces electromagnetic interference. E: It improves axial resolution.
D: It reduces electromagnetic interference.
Increasing the number of acoustic scan lines in one frame improves which of the following? A: Temporal resolution B: Axial resolution C: Elevational resolution D: Lateral resolution E: Contrast resolution
D: Lateral resolution
What is being measured on the three rods in the center of this image? See image for question #578 A: Axial resolution B: Penetration C: Elevational resolution D: Lateral resolution E: Temporal resolution
D: Lateral resolution
Which transducer has the same distance between the scan lines in both the near and far fields? A: Convex array B: Phased array C: Curvilinear array D: Linear array E: Mechanical sector
D: Linear array
Which control optimization should you make to improve color Doppler sensitivity to slow flow? A: Lower the packet size B: Lower the transmitted ultrasound frequency in Doppler C: Raise the PRF D: Lower wall filter setting E: Lower the threshold
D: Lower wall filter setting
Which of the following human tissues has the highest rate of attenuation of an ultrasound wave? A: Liver B: Fat C: Fluid D: Lung E: Blood vessels
D: Lung
You are using an ultrasound examination mode that is useful for measuring dimensions of structures. This mode produces a display more similar to a tracing rather than an actual anatomic picture. Which of the following most closely matches this description? A: Duplex mode B: B-mode C: C-mode D: M-mode E: P-mode
D: M-mode
The sound beam can be focused by all of the following except: A: Acoustic mirror B: Acoustic lens C: Curved crystal D: Matching layer E: Electronic phasing
D: Matching layer
For a linear array transducer consisting of a single row of elements, what method is most used to focus the beam in the elevational direction? A: Transmit focusing B: Dynamic receive focusing C: Aperture focusing D: Mechanical focusing E: None of the above
D: Mechanical focusing
Which answer provides the best explanation for the reason that the frame rate decreases when color Doppler is activated? A: The color Doppler pulse length is longer B: There are more focal zones when color is active C: The system memory resources are challenged D: More pulses are fired on each line of sight E: All of the above
D: More pulses are fired on each line of sight
What is the purpose of applying multiple matching layers to the transducer face? A: The gel gradually erodes the matching layer, and using multiple layers lengthens the life of the transducer assembly. B: Because the impedance of tissue is quite variable from one patient to the next, multiple matching layers improve the likelihood of providing a close impedance match to each patient. C: Each individual coating of the matching layer contributes to the damping of the sound pulse, which results in improved axial resolution D: Multiple matching layers result in increased transducer bandwidth. E: Each coating of the matching layer provides focusing at a specific depth. With multiple layers, multiple points of focus are possible.
D: Multiple matching layers result in increased transducer bandwidth.
What type of focusing decreases the frame rate? A: Mechanical focusing B: Dynamic receive focusing C: Dynamic aperture focusing D: Multiple transmit focusing E: Curved crystal focusing
D: Multiple transmit focusing
You will see aliasing of the Doppler spectrum occurs whenever the frequency shift exceeds: A: Twice the pulse repetition frequency B: Three times the pulse repetition frequency C: One-third the pulse repetition frequency D: One-half the pulse repetition frequency E: One-fourth the pulse repetition frequency
D: One-half the pulse repetition frequency
These images show flow within the sac of a Pseudoaneurysm. Image A shows more color fill than image B. What color control was changed from image A to image B? See images for question #507 A: Gain B: Threshold C: Transmit frequency D: PRF E: Transmit power
D: PRF
Which of the following would most likely have the highest SPTA value? A: CW Doppler B: B-mode real-time scanners C: Static B-mode scanners D: PW Doppler E: Fetal monitor Doppler
D: PW Doppler
You are using a transducer that produces a beam with a very wide slice thickness. Which of the following problems are you most likely to encounter as a result? A: Increased near field reverberations in fluid structures B: Increased side lobes C: Decreased penetration D: Partial volume artifact E: Decreased frame rate
D: Partial volume artifact
A longitudinal wave is characterized by: A: A wave that demonstrates only Sagittal imaging planes. B: Randomized particle motion. C: A constant acoustic velocity of 1,540m/s. D: Particle motion occurring in the same direction as propagation. E: Particle motion occurring perpendicular to the direction of propagation.
D: Particle motion occurring in the same direction as propagation.
Which of the following terms denotes the time it takes for one cycle to occur? A: Frequency B: Amplitude C: Wavelength D: Period E: Pressure
D: Period
Electronic steering is most commonly applied to which of the following real-time transducers? A: Annular array B: Sequential linear array C: Mechanical sector D: Phased array E: Segmental linear array
D: Phased array
The optimal transducer technology for cardiac scanning is: A: Curved array B: Tightly curved array C: Linear array D: Phased array E: Mechanical sector
D: Phased array
The picture elements in a scan converter matrix are termed: A: Decimals B: Binary numerals C: Bits D: Pixels E: Bytes
D: Pixels
What sound parameter is determined only by the medium? A: Frequency B: Period C: Intensity D: Propagation speed E: None of the above
D: Propagation speed
What system control should be adjusted to optimize this waveform? See image for question #472 A: Wall filter B: Packet size C: Gain D: Pulse repetition frequency E: Sample volume size
D: Pulse repetition frequency
The packet size in color Doppler refers to the number of: A: Pulses per second B: Sample volumes per scan line C: Scan lines per unit area D: Pulse-listen cycles per acoustic scan line E: Pulses required to create one frame
D: Pulse-listen cycles per acoustic scan line
The packet size in color Doppler refers to the number of: A: Pulses per second B: Sample volumes per scan line C: Scan lines per unit area D: Pulses per acoustic scan lines E: Pulses per frame
D: Pulses per acoustic scan lines
What feature would you use if you wish to recall a previous exam from the PACS system to your ultrasound machine? A: Storage commitment B: Worklist C: DICOM store D: Query/retrieve E: HIPAA
D: Query/retrieve
The waveform you obtained from a arterial stenosis demonstrates aliasing. If you increase the pulse repetition frequency to eliminate the aliasing, what artifact could be introduced? A: Multipath reflections B: Spectrum mirror image C: Propagation speed error D: Range ambiguity E: Refraction
D: Range ambiguity
Another name for axial resolution is: A: Transverse resolution B: Azimuthal resolution C: Angular resolution D: Range resolution E: A and C
D: Range resolution
What term refers to regions of decreased particle density in a sound beam? A: Attenuation B: Transmission C: Compression D: Rarefaction E: Reverberation
D: Rarefaction
Which physics concept best explains the difference in signal strength between the 5.0 and 6.3 MHz Doppler frequencies? See images for question #509 A: The Reynolds number B: Poisiuelle's law C: Bernoulli effect D: Rayleigh scattering E: Cavitation
D: Rayleigh scattering
What three colors are used on a color monitor to produce the range of available colors? A: Red, purple, yellow B: Yellow, green, blue C: Blue, yellow, red D: Red, green, blue E: Blue, white, red
D: Red, green, blue
Increasing the wall filter during Doppler sampling will: A: Increase visibility of low velocity signals B: Increase spectral broadening C: Decrease bandwidth D: Reduce display of low-frequency shifts E: Reduce aliasing
D: Reduce display of low-frequency shifts
What is the result of increasing the wall filter during Doppler sampling? A: Increased visibility of low velocity signals B: Increased spectral broadening C: Decreased bandwidth D: Reduced display of low-frequency Doppler signals E: Reduction of aliasing
D: Reduced display of low-frequency Doppler signals
If sound waves of 3MHz, 5MHz, and 10MHz are transmitted through the same section of anatomy, reflections from which frequency would reach the transducer first? A: 3MHz B: 5MHz C: 10MHz D: Reflections from all three frequencies would have nearly identical transmit times. E: It is not possible to predict which will arrive first.
D: Reflections from all three frequencies would have nearly identical transmit times.
In ultrasound systems, the range equation is used to determine which of the following? A: Reflector amplitude B: Reflector frequency C: Reflector direction D: Reflector depth E: Reflector size
D: Reflector depth
What is the source of the echoes depicted by the arrows in this image of the kidney? See image for question #387 A: Side lobes B: Grating lobes C: Refraction D: Reverberation E: Multipath reflections
D: Reverberation
In this image of an arterial stenosis, the waveform indicates post stenotic Turbulence. What term describes the point at which flow becomes turbulent? See images for question #504 A: Poiseuilles's law B: Bernouille's law C: Starling's law D: Reynolds number E: Doppler equation
D: Reynolds number
Which artifact is associated with resonance of a gas bubble? A: Grating lobes B: Comet tail C: Acoustic speckle D: Ring-down E: Refraction
D: Ring-down
What component is necessary for a real-time B-mode scanner but is not present in an A-mode scanner? A: Clock B: Transmitter C: Transducer D: Scan converter E: Receiver
D: Scan converter
Another term for Nonspecular reflection: A: Destructive interference B: Refraction C: Diffraction D: Scattering E: Absorption
D: Scattering
What is the main advantage of using an Intracavitary probe compared to a standard transducer? A: The Intracavitary probe has superior focusing capabilities because of the increased radius of the curved probe face. B: The Intracavitary probe uses a lower frequency that provides superior penetration and closer inspection of the pelvic structures. C: The Intracavitary probe does not demonstrate side lobes or grating lobes because of the close spacing and curvature of the elements. D: Since the Intracavitary probe is closer to the area of interest, a higher frequency transducer can be used, resulting in superior spatial resolution. E: Bioeffects are greatly reduced with the Intracavitary probe because of its frequency range and power output.
D: Since the Intracavitary probe is closer to the area of interest, a higher frequency transducer can be used, resulting in superior spatial resolution.
The following two Sagittal images of an artery were obtained with different transducers. What type of resolution is limiting visualization of the arterial lumen in the image on the left? See image for question #392 A: Axial B: Lateral C: Temporal D: Slice thickness E: Contrast
D: Slice thickness
What term would describe a Doppler waveform obtained at location "C" in this depiction of an arterial stenosis? See image for question #489 A: Parabolic flow profile B: Laminar flow profile C: Plug flow profile D: Spectral broadening flow profile E: Dampened flow profile
D: Spectral broadening flow profile
If sound did not attenuate with increasing depth, what system control would you no longer need? A: Dynamic range B: Reject C: Frame averaging D: TGC E: Master gain
D: TGC
Which of the following occurs when you lower the pulse repetition frequency? A: The wall filter is increased B: The frame rate is increased C: The line density is increased D: The Nyquist limit is decreased E: The Doppler frequency is decreased
D: The Nyquist limit is decreased
What occurs when you image a structure with oblique incidence? A: A very strong reflection will occur since this is the optimal angle for imaging. B: All of the sound will be reflected due to the poor scanning angle. C: All of the sound will be transmitted due to the poor scanning angle. D: The angle of reflection will be oriented away from the transducer resulting in decreased visualization of the structure. E: The amount of scattering will be reduced with a scanning angle of 45 degrees resulting in a cleaner image with reduced artifactual echoes.
D: The angle of reflection will be oriented away from the transducer resulting in decreased visualization of the structure.
When you perform a Doppler exam the frequency of the transmitted signal is determined by: A: Backing material B: Attenuation factor of the tissue C: Bandwidth D: The frequency of the electrical signal applied to the transducer. E: Amplitude
D: The frequency of the electrical signal applied to the transducer.
You have decreased the acoustic power by -3dB. Which of the following most accurately describes the adjustment? A: The intensity has been quadrupled. B: The intensity has been quartered. C: The intensity has been increased 10 times. D: The intensity has been halved. E: The intensity has not been altered.
D: The intensity has been halved.
What does mechanical index indicate on an ultrasound system? A: The maximum temperature increase in tissue B: The minimum temperature increase in tissue C: Acoustic power in milliwatts D: The liklihood of cavitation during an ultrasound exam E: Minutes of exposure time before tissue heating is too great
D: The liklihood of cavitation during an ultrasound exam.
Blood vessels usually appear Anechoic on B-mode imaging because: A: They are empty B: The red blood cells cannot reflect the sound beam C: The red blood cells absorb the sound D: The reflection from the red blood cells is too weak to be displayed E: The red blood cells are moving too fast to produce a reflection
D: The reflection from the red blood cells is too weak to be displayed
According to Snell's law the angle of transmission is related to the incident beam angle and: A: The amount of acoustic impedance mismatch at an interface. B: The change in frequency that occurs at an interface. C: One-half of the angle of incidence. D: The relative speeds of sound in the two media. E: The percentage of diffraction distal to the interface.
D: The relative speeds of sound in the two media.
When you are educating your patient about the sonographic exam, sound travels through air from your mouth to your patients ears. Which of the following is true regarding the speed of sound travel through air? A: The speed of sound in air is greater than the speed of light. B: The speed of sound in air is greater than the speed of sound in soft tissue. C: The speed of sound in air is not predictable. D: The speed of sound in air is slower than the speed of sound in soft tissue. E: The speed of sound in air is equal to the speed of sound in soft tissue.
D: The speed of sound in air is slower than the speed of sound in soft tissue.
What error will occur if the angle correct cursor is NOT adjusted parallel to the vessel wall? A: The frequency shift will be underestimated B: No Doppler frequency shift will be detected C: Mirror imaging of the Doppler spectrum will occur D: The velocity estimation will be inaccurate E: Aliasing of the Doppler spectrum will occur
D: The velocity estimation will be inaccurate
While performing a Doppler study, the measurement of the Doppler angle of incidence was underestimated. What error will result from this mistake? A: The frequency shift will be underestimated B: No Doppler frequency shift will be detected C: Mirror imaging of the Doppler spectrum will occur D: The velocity estimation will be inaccurate E: Aliasing of the Doppler spectrum will occur
D: The velocity estimation will be inaccurate
What type of transducer was used to create this image of the uterus? See image for question #257 A: Linear array B: Phased array C: Single-element mechanical D: Tightly curved array E: Sector
D: Tightly curved array
Dynamic receive focusing uses: A: Mechanical means to focus the beam B: Time delays to excite array elements C: Variable number of elements to form the transmitted beam D: Time delays before echo signals from array elements are combined E: All of the above
D: Time delays before echo signals from array elements are combined
What is the order in which the signal travels in the ultrasound system? A: Transducer, receiver, display, scan converter B: Scan converter, transducer, receiver, display C: Scan converter, receiver, transducer, display D: Transducer, receiver, scan converter, display E: Receiver, transducer, scan converter, display
D: Transducer, receiver, scan converter, display
Which scanning mode does NOT rely on the principle of echo ranging to determine interface location? A: M-mode B: Pulsed-wave Doppler C: Static B-mode D: Transmission E: A-mode
D: Transmission
You have encountered spectral broadening of the internal carotid artery waveform. This most likely indicates: A: Slow heart rate B: Tachycardia C: Accelerated flow D: Turbulent flow E: High resistance flow
D: Turbulent flow
You are most like to see a color bruit in which of the following cases? A: Trickle flow within a small residual lumen B: Damped flow proximal to a high-grade stenosis C: Chronic vessel occlusion D: Turbulent flow distal to a high-grade stenosis E: Normal arterial flow
D: Turbulent flow distal to a high-grade stenosis
You are imaging a 3D data set that has anisotropic resolution. What does this mean? A: Spatial resolution is better than temporal resolution B: Spatial resolution is equal in all dimensions C: Contrast resolution is superior to spatial resolution D: Unequal resolution is present between imaging planes E: Elevation resolution and contrast resolution are the same
D: Unequal resolution is present between imaging planes
What statement is correct regarding the comparison of these two waveforms? See images for question #526 A: Waveform A shows a delayed systolic upstroke compared to B B: Waveform A shows decreased spectral broadening compared to B C: Waveform A indicates the presence of proximal disease and waveform B is normal D: Waveform A indicates a low-resistance state compared to waveform B E: Waveform A shows flow toward the transducer and waveform B shows flow away from the transducer
D: Waveform A indicates a low-resistance state compared to waveform B
In this color map, what color represents the highest positive Doppler shift? See images for question #532 A: Dark red B: Dark blue C: Black D: Yellow/orange E: Cyan
D: Yellow/orange
Which color would represent an aliased Doppler signal from flow coursing away from the transducer? See images for question #532 A: Dark red B: Dark blue C: Black D: Yellow/orange E: Cyan
D: Yellow/orange
You are using a transducer with poor elevation resolution. What problem will most likely be encountered as a result? A: Small structures closely spaced together along the path of the beam will not be separated B: Two closely spaced structures in a plane perpendicular to the beam will not be separated C: You will not be able to accurately measure structures oriented perpendicular to the beam D: You will not be able to clear Anechoic tubes oriented with their axis in the scan plane E: High-contrast spherical objects will not be correctly imaged
D: You will not be able to clear Anechoic tubes oriented with their axis in the scan plane
You are performing a sonogram and notice that the TI reading is 1. What does this indicate? A: The patients temperature has increased 1 degree C as a result of the ultrasound scan. B: The patients temperature has increased 2 degrees C as a result of the ultrasound scan. C: You must limit your scanning to 1 minute. D: The output level is high enough that temperature could increase as much as 1 degree C if the transducer were held stationary. E: The temperature at the focal point has increased by 1 degree C and scanning time must be reduced to 4 minutes
D: the output level is high enough that temperature could increase as much as 1 degree C if the transducer were held stationary.
One way to reduce ringing is to ______ after it has been excited by an electrical signal from the ultrasound system.
Dampen the crystal
Backing material is also called the _______.
Damping element
In diagnostic ultrasound it is important to quantify the strength of sound beams as they are created by transducers and travel through the body. In addition, electrical signal strength and the brightness of images need to be quantified. The common method of measuring these kinds of signals is the ______.
Decibel
The unit of sound intensity is the _______.
Decibel
A standard measurement tool used to report changes in the degree of weakening or the extent of amplification.
Decibel notation
The interference of a pair of out-of-phase waves results in the formation of a single wave of lesser amplitude than either of its components and is termed?
Deconstructive interference
Penetration is ______ with increasing frequency.
Decreased
The density of particles is ____ during rarefaction.
Decreased
Means that transducers with damping material are less able to convert low level sound reflections into meaningful electrical signals during reception.
Decreased sensitivity
As depth of view increases, pulse repetition frequency ______.
Decreases
As frequency increases, wavelength _______.
Decreases
As materials become more dense the speed of sound in the material ______.
Decreases
Focusing improves lateral resolution because it _____ beam width.
Decreases
Propagation speed ____ with increased density.
Decreases
When the PRF increases, the PRP ______.
Decreases
Lower frequency sound beams spread out or diverge more in the ______ zone.
Deep far
Higher frequency sound results in a ______ focus.
Deeper
Increasing diameter results in a ____ focus.
Deeper
With linear phased arrays the spike pattern that is least curved produces the Beam with the ______ focus.
Deepest
Long pulses _____ axial resolution.
Degrade
Concentration of mass in a volume.
Density
Describes the relative weight of material.
Density
By changing the listening time sonographers alter the _____ of the image.
Depth
Lateral resolution changes with ______.
Depth
The optimal time delays used during receive focusing change depending upon the ______ at which the reflection was created.
Depth
The x-axis in A-mode represents?
Depth
The x-axis in b-mode represents?
Depth
The y-axis in b-mode represents?
Depth
What is the equation for depth?
Depth (mm) = 1.54mm/,us x go-return time (,us)/ 2
The range equation can be stated as:
Depth = 1/2 x speed of sound in tissue x round trip travel time
TGC is also called?
Depth gain compensation
A-modes are accurate in determining the _______.
Depth of reflectors
Changing the ______ of a scan also changes the duty factor.
Depth of view
Describes the maximum distance into the body that an ultrasound system is imaging.
Depth of view
PRF is related only to ______.
Depth of view
The sonographer can change pulse repetition frequency by adjusting the ________.
Depth of view of a scan
Piezoelectric properties can be _____ by exposure to high temperature.
Destroyed
Occurs when the resultant wave is smaller than one of its components.
Destructive interference
When a sound beam strikes a tissue boundary at a 90 degree angle reflection occurs only if the media on either side of the boundary have ________.
Different impedances
What is required for reflection with normal incidence?
Different impedances are required
With linear sequential array transducers the sound pulses originate from ______________ when different sets of crystals are excited.
Different locations along the face of the probe
Requires the sound to pass through a small aperture.
Diffraction
The general term for various phenomena in which waves from different parts of a source add or subtract.
Diffraction
An advantage of _____ reflections is that interfaces at suboptimal angles to the sound beam can still produce reflections that the transducer will receive.
Diffuse
Occurs when the sound beam strikes a large rough surface.
Diffuse reflection
What does DICOM stand for?
Digital Imaging and Communications In Medicine
There is a _____ relation between absorption and frequency.
Direct
Absorption is _____ related to frequency.
Directly
Distance and attenuation are ______ related.
Directly
Frequency and attenuation are ______ related.
Directly
Frequency and focal depth are _____ related.
Directly
In a pulsed wave transducer the speed of sound in PZT and the frequency of sound are _____ related.
Directly
In soft tissue the attenuation coefficient and the frequency are _____ related.
Directly
PRP is _______ related to the maximum imaging depth.
Directly
Pulse repetition period and imaging depth are ______ related.
Directly
Q factor is _____ related to the pulse length.
Directly
Scattering is ______ related to frequency.
Directly
Spatial pulse length and pulse duration are ______ related.
Directly
Stiffness and propagation speed are ______ related.
Directly
The distance that the sound travels _____ affects attenuation.
Directly
The time-of-flight is ______ related to the depth that sound pulse travels.
Directly
Transducer diameter and focal depth are ____ related.
Directly
Pulse duration is ______ to period.
Directly proportional
Pulse duration is _______ to the number of cycles in the pulse.
Directly proportional
Spatial pulse length is ______ to the number of cycles in the pulse.
Directly proportional
Spatial pulse length is _______ to wavelength.
Directly proportional
Amplitude, power, and intensity tend to be _______, therefore, when intensity increases power and amplitude also increase.
Directly related
Two items that are associated that when one item increases, the other increases.
Directly related or proportional
The active elements of annular array transducers appear ______.
Disc-like
The application of a chemical agent to reduce or eliminate infectious organisms on an object.
Disinfection
Pressure is reduced _____ to a stenosis in turbulent flow.
Distal
Measure of particle motion.
Distance
Spatial pulse length has units of?
Distance
Decrease by a factor means to ______.
Divide
How do you calculate intensity?
Divide the beams power by the beams cross-sectional area
Aliasing ____ occur with CW Doppler.
Does not
Decibel notation ______ measure absolute numbers.
Does not
Frequency ____ affect propagation speed.
Does not
Propagation speed ____ affect attenuation of the sound beam.
Does not
With rainbow maps, the green ______ indicate turbulence.
Does not
The advantage of attenuation coefficient in describing sound weakening is that its value _______ as path length changes.
Does not change
When the Doppler beam encounters high flow velocities, a large frequency difference occurs between the transmitted and received frequencies. This frequency difference is know as the _________.
Doppler frequency shift
What is the equation for duty factor?
Duty Factor (%) = Pulse Duration/PRP x 100
The ______ describes the relationship of beam intensities with time.
Duty factor
The percentage of time that the ultrasound is being transmitted.
Duty factor
The percentage or fraction of time that the system is transmitting a pulse.
Duty factor
With ______ the echoes that are received first are held in delay circuitry until all of the echoes from the same depth have been received.
Dynamic Receive Focusing
A function of the beam former and Pulser. It is performed during transmit and receive beam forming.
Dynamic aperture
A typical value for the duty factor in diagnostic sonographic imaging is: A: 80-100% B: 50-75% C: 25-45% D: 5-20% E: 0.1-1%
E: 0.1-1%
Which of the following represents the number 1234 in scientific notation? A: 0.1234 B: 0.1234 x 10 3 C: 1234 x 10 1 D: 1234 x 10-1 E: 1.234 x 10 3
E: 1.234 x 10 3
What is the maximum number of shades of gray in an 8-bit digital scan converter? A: 16 B: 32 C: 64 D: 128 E: 256
E: 256
You are performing a carotid duplex examination with the following parameters: 5 MHz Doppler frequency, 6 kHz PRF, 4 cm depth, and 1.5 mm sample volume length. What is the aliasing frequency? A: 5 MHz B: 6 kHz C: 12 kHz D: 1.5 MHz E: 3 kHz
E: 3 kHz
If you make a mistake in the measurement of the Doppler angle, the error in velocity estimation will be greatest at which Doppler angle? A: 0 degrees B: 30 degrees C: 45 degrees D: 60 degrees E: 70 degrees
E: 70 degrees
The Doppler waveform you have obtained from a collateral channel shows high resistance compared to the contralateral normal artery. The increased resistance may be attributed to: A: Decreased tube diameter B: Increased vessel length C: Decreased resistance in the vascular bed D: All of the above E: A and B
E: A and B
The end result of the issue from the above question is: Answer to question #590: A: Damage to the lens or transducer crystals A: Degradation of image quality B: Underestimation of maximum flow velocity C: Electrical shock D: Overheating E: A and B
E: A and B
Which of the following will improve the artifact you are imaging in the previous question? Answer to question #419: Acoustic speckle A: Use frame averaging B: Use compound imaging C: Reduce the output power D: Increase the overall gain E: A and B
E: A and B
What should you do to avoid nosocomial and cross-infection with sonographic probes? A: Probe cleaning should always precede high-level disinfection. B: Covering a probe with a condom is a sufficient barrier to infection for intracavitary probes. C: Disinfection using a germicide compatible with the transducer is indicated when the probe is in contact with mucous membranes. D: Alcohol soak of each probe should occur between patients. E: A and C
E: A and C
Attenuation of the sound beam is affected by: A: Absorption B: Scattering C: Reflection D: Propagation speed E: A, B, and C
E: A, B, and C
Which display mode may be used to calculate distance measurements? A: A-mode B: B-mode C: M-mode D: B and C only E: A, B, and C
E: A, B, and C
A linear array will produce which of the following image shapes? See image for question #230 and 231 A: A or B B: B or C C: C or D D: D or E E: A, C, or E
E: A, C, or E
Which transducer would demonstrate a waveform ABOVE the zero baseline? See image for question #457 A: A B: B C: C D: D E: All except for E
E: All except for E
An ultrasound system preventative maintenance program should include: A: Cleaning of air filters B: Visual inspection of probes C: Transducer testing D: External cleaning of the system E: All of the above
E: All of the above
Attenuation of the sound beam increases with increasing: A: Path length B: Absorption C: Frequency D: Scattering and reflection E: All of the above
E: All of the above
Axial resolution is improved with: A: Increased bandwidth B: Shorter pulse length C: Shorter wavelength D: B and C E: All of the above
E: All of the above
Requirements of magnetic field tracking for 3D reconstruction include: A: Minimization of electromagnetic interference B: Transmitter must be in close proximity to the receiver C: Ferrous metals must not be within the electromagnetic field D: A and B only E: All of the above
E: All of the above
The Reynolds number increases with increasing: A: Flow speed B: Vessel diameter C: Blood density D: Blood flow viscosity E: All of the above
E: All of the above
The presence of the systolic spectral window of the Doppler waveform is affected by: A: Sample volume size B: Turbulent flow C: Doppler gain D: Position of the Doppler sample volume E: All of the above
E: All of the above
Use of a transducer should be discontinued if a crack appears in the following area: See image for question #586 A: A B: B C: C D: D E: All of the above
E: All of the above
Using the Modality Worklist has the advantage of: A: Avoiding the need to type patient information B: Reducing patient information error C: Speeding up patient preparation time D: Easily confirming patient information E: All of the above
E: All of the above
What can you test with a Doppler flow phantom? A: Range-gate accuracy B: Spectral Doppler velocity accuracy C: Color Doppler penetration D: A and B only E: All of the above
E: All of the above
What must be known to convert the Doppler shift frequency spectrum into velocities? A: Doppler frequencies B: Angle of incidence C: Speed of sound in tissue D: Ultrasound frequency E: All of the above
E: All of the above
When you select compound imaging, which artifact is less likely to be observed? A: Refraction B: Shadowing C: Enhancement D: Acoustic speckle E: All of the above
E: All of the above
Which of the following could be a source of color Doppler signal? A: Blood flow B: Breathing motion C: Cardiac motion D: Transducer motion E: All of the above
E: All of the above
Which of the following could be used to increase the color frame rate for a cardiac image? A: Decrease the image width B: Decrease the packet size C: Decrease the line density D: A and B E: All of the above
E: All of the above
Which of the following increases as frequency increases? A: Absorption B: Scattering C: Attenuation D: A and C only E: All of the above
E: All of the above
Which of the following interactions of sound and tissue decreases the intensity of the transmitted beam? A: Absorption B: Reflection C: Scattering D: Conversion of sound to heat E: All of the above
E: All of the above
Which of the following should be regularly checked as a component of quality control program? A: System penetration B: Image uniformity C: Assurance of electrical safety D: Distance measurement accuracy E: All of the above
E: All of the above
Which of the following transducers produces side lobes? A: Mechanical sector B: Linear sequential array C: Phased array D: Convex array E: All of the above
E: All of the above
If you wish to use an array transducer that allows you to control transmit focal depth, what type would you select? A: Linear array B: Convex array C: Phased array D: Annular array E: Any of the above
E: Any of the above
What term is used to describe the reduction in the intensity of sound as it propagates through tissue? A: Diffraction B: Refraction C: Reflection D: Absorption E: Attenuation
E: Attenuation
The rods depicted by the arrows in this phantom are used to determine what leature of the machine? See image for question #574 A: Contrast resolution B: Penetration C: Lateral resolution D: Measurement accuracy E: Axial resolution
E: Axial resolution
Using a hydrophone you can measure? A: Impedance B: Pressure amplitude C: Duty factor D: All of the above E: B and C only
E: B and C only
Transducers should NOT be cleaned with: A: Soap and water B: Ultraviolet C: Autoclave D: Gas E: B, C, and D
E: B, C, and D
Which transducer would have a lower line density in the far field compared to the near field? A: Linear array B: Curved array C: Tightly curved array D: Phased array E: B, C, and D
E: B, C, and D
The spectrum of frequencies emitted by a pulsed-wave transducer is known as: A: Reynolds number B: Center frequency C: F-number D: Resonance frequency E: Bandwidth
E: Bandwidth
What limitation is present when you use high-PRF Doppler? A: Frame rate B: Spatial resolution C: Sensitivity to slow flow D: Range resolution E: Both C and D
E: Both C and D
What Reynolds number would result in turbulent flow? A: 200 B: 300 C: 2000 D: 3000 E: C and D
E: C and D
Which intensity parameter is not applicable for continuous-wave ultrasound? A: SATA B: SPTA C: SPPA D: SAPA E: C and D
E: C and D
You want to use 3D imaging to display an anatomic structure because 3D has the following advantage over 2D imaging: A: Higher frame rates B: Better spacial resolution C: Ability to display image planes impossible to obtain with 2D imaging D: Ability to display orthogonal planes simultaneously E: C and D
E: C and D
Which of the following ultrasound examinations would require the highest frame rate? A: Small parts B: Abdominal C: Pelvic D: Vascular E: Cardiac
E: Cardiac
You may observe sound attenuation by all of the following EXCEPT: A: Reflection B: Scattering C: Conversion of sound to heat D: Absorption E: Compression
E: Compression
The ability to distinguish between adjacent structures that produce echoes of similar amplitude is termed: A: Spatial resolution B: Axial resolution C: Lateral resolution D: Temporal resolution E: Contrast resolution
E: Contrast resolution
What type of transducer was used to obtain this image? See image for question #227 A: Linear array B: Sector C: Phased array D: Micro convex E: Curved array
E: Curved array
What factor LEAST influences lateral resolution? A: Frequency B: Focus depth C: Beam width D: Transducer diameter E: Damping
E: Damping
While evaluating the liver vasculature with color Doppler, you are unable to obtain signals from the deeper vessels. What should you do to enhance your ability to demonstrate deep flow? A: Decrease the packet size B: Increase the scan line density C: Increase the wall filter D: Increase the pulse repetition frequency E: Decrease the ultrasound frequency
E: Decrease the ultrasound frequency
Increasing the frequency on a multifrequency transducer from 3.5MHz to 5.0MHz will: A: Increase the sound propagation speed B: Increase the pulse length C: Increase penetration D: Decrease the pulse repetition frequency E: Decrease the wavelength
E: Decrease the wavelength
What would you change if the image does not show adequate penetration and the far field displays noise instead of tissue? A: Turn on compound imaging. B: Move the focal position to a more superficial location. C: Use an acoustic stand-off pad. D: Increase TGC. E: Decrease transmit frequency.
E: Decrease transmit frequency.
What is meant by the dead zone in performance testing? A: B-mode penetration distance B: Level at which the ultrasound signal is the same strength as the electronic noise C: Doppler signal obtained at 90 degrees D: Doppler penetration distance E: Distance from the transducer to the first identifiable echo
E: Distance from the transducer to the first identifiable echo
Which echo amplitude in the following illustration would produce the brightest dot on a B-mode display? See image for question #335 A: A B: B C: C D: D E: E
E: E
Which transducer would not detect a Doppler frequency shift? See image for question #457 A: A B: B C: C D: D E: E
E: E
While performing an ultrasound examination, you decide to adjust the system settings to improve the image. Which of the following is NOT user-adjustable? A: Frequency B: Power C: Gain D: Compression E: Echo arrival time
E: Echo arrival time
What type of resolution is most affected by the mechanical focus on a linear array transducer? A: Lateral resolution B: Contrast resolution C: Temporal resolution D: Axial resolution E: Elevational resolution
E: Elevational resolution
What is another name for the Hyperechoic artifact distal to a fluid structure? See image for question #388 A: Refraction B: Shadowing C: Speckle D: Grating lobe E: Enhancement
E: Enhancement
The location where the sound beam reaches its narrowest diameter is known as the: A: Fraunhofer zone B: Beam area C: Fresnel zone D: Curie point E: Focal zone
E: Focal zone
Which of the following is a commonly recommended ingredient in cleansers for intracavitary probes? A: Acetone B: Iodine C: Betadine D: Bleach E: Gluteraldehyde
E: Gluteraldehyde
What advantage is obtained by steering a linear array transducer to create a trapezoidal shape to the display as demonstrated in this image? See image for question #256 A: Improved lateral resolution B: Improved axial resolution C: Improved contrast resolution D: Improved elevational resolution E: Improved field of view
E: Improved field of view
Which of the following will NOT improve axial resolution? A: Increased damping B: Increased transducer frequency C: Increased bandwidth D: Decreased pulse length E: Increased focusing
E: Increased focusing
The following advantage is associated with use of the MI and TI indices: A: The system will automatically adjust parameters to limit exposure under adverse conditions. B: The system will beep to notify the sonographer when indices are too great. C: The system will shut down when exposure becomes too great. D: The sonographer can easily dial in a safe exposure limit for each patient. E: Information is available on the screen to help the sonographer implement the ALARA principle.
E: Information is available on the screen to help the sonographer implement the ALARA principle.
What is the purpose of the SMPTE test pattern? A: It is used to determine transducer sensitivity B: It is used to measure penetration C: It is used to measure axial resolution D: It is used to measure lateral resolution E: It is used to aid in the setup and quality assurance of displays and cameras
E: It is used to aid in the setup and quality assurance of displays and cameras
You have been requested to image a superficial mass and to adjust your equipment to optimize spatial resolution. Spatial resolution consists of: A: Contrast and Temporal resolution B: Temporal and axial resolution C: Axial and contrast resolution D: Contrast and lateral resolution E: Lateral and axial resolution
E: Lateral and axial resolution
When you increase the scan line density in the B-mode image, you improve: A: Temporal resolution B: Contrast resolution C: Slice thickness D: Axial resolution E: Lateral resolution
E: Lateral resolution
In the following waveform, the end-diastolic flow velocity cannot be measured. What control adjustment should be performed to obtain this measurement? See image for question #484 A: Increase the pulse repetition frequency B: Decrease the angle of incidence C: Lower the zero baseline D: Increase the Doppler gain E: Lower wall filter
E: Lower wall filter
What determines the speed of sound? A: Frequency of sound wave B: Intensity of sound wave C: Attenuation of sound wave D: Reflection of sound wave E: Medium through which sound wave passes
E: Medium through which sound wave passes
What is the maximum velocity limit for a 3 MHz CW Doppler unit operating at a depth of 4 cm? A: 40 cm/s B: 200 cm/s C: 2.5 m/s D: 4 m/s E: None of the above
E: None of the above
What is the maximum velocity limit for a 3 MHz CW Doppler unit operating at a depth of 4 cm? A: 40 cm/s B: 200 cm/s C: 2.5 m/s D: 4 m/s E: None of the above
E: None of the above
Which of the following conditions will result in aliasing of the Doppler frequency shift using continuous-wave Doppler? A: PRF 10 kHz, frequency shift 4 kHz B: PRF 12 kHz, frequency shift 8 kHz C: PRF 5 kHz, frequency shift 2.3 kHz D: PRF 8 kHz, frequency shift 5 kHz E: None of the above
E: None of the above
Which of the following occurs when you use the maximum system gain? A: Increased tissue heating B: Increased risk of cavitation C: Fluid particle streaming D: Increased sound absorption E: None of the above
E: None of the above
You are imaging with a 5MHz linear array transducer. What sound parameter stays constant as the beam propagates through the tissue? A: Frequency B: Intensity C: Amplitude D: Wavelength E: None of the above
E: None of the above
A-mode display is most commonly used for what type of ultrasound imaging? A: Small parts B: Abdominal C: Cardiac D: Vascular E: Opthalmologic
E: Opthalmologic
You have the ability to adjust the following controls during an abdominal ultrasound study. Which control most closely affects patient exposure? A: Receiver overall gain B: TGC C: Dynamic range D: Reject E: Output power
E: Output power
A commonly used system to handle the archiving and electronic distribution of sonographic images using a DICOM format is: A: VHS B: DVD C: USB D: MOD E: PACS
E: PACS
What flow characteristic is depicted in this illustration? See image for question #486 A: Turbulent flow B: Blunt flow profile C: Flat flow profile D: Stenotic flow profile E: Parabolic flow profile
E: Parabolic flow profile
What array transducer fires all of the elements for each acoustic scan line, using small time delays to steer the beam? A: Linear segmental array B: Convex array C: Annular array D: Linear sequential array E: Phased array
E: Phased array
In medicine what do the initials "PHI" indicate? A: Private health indicator B: Personal heart index C: Personal health information D: Private health institute E: Protected health information
E: Protected health information
What artifact is being described in the previous question? Question #403: While scanning a curved structure, you notice shadowing at the lateral edges of the structure. What is required for this artifact to occur? A: Grating lobes B: Comet tail C: Acoustic speckle D: Ring-down E: Refraction
E: Refraction
Which of the following sound interactions produced the shadows indicated by the arrows on this image?
E: Refraction
Electronic noise is reduced in the ultrasound system by this method: A: Demodulation B: Compensation C: Rectification D: Amplification E: Rejection
E: Rejection
Which statement is NOT true regarding lateral resolution? A: It is equal to beam width. B: It is improved by focusing. C: It is defined as the minimum separation required to resolve two structures perpendicular to the beam axis. D: It is also known as azimuthal resolution. E: Remains constant throughout scanning depth.
E: Remains constant throughout scanning depth.
The ultrasound system in your lab has a transducer with a small footprint. This kind of transducer has the following disadvantage: A: It cannot be focused in the elevation direction. B: The field of view in the far field is only 1/4 the diameter of the transducer. C: The near field lateral resolution is poor. D: The Q value is very high. E: Resolution is degraded at large distances.
E: Resolution is degraded at large distances.
Which of the following would show the highest intensity value? A: SATP B: SATA C: Im D: SPPA E: SPTP
E: SPTP
What interaction of ultrasound and tissue is primarily responsible for imaging the internal structure of organs? A: Specular reflection B: Refraction C: Diffraction D: Destructive interference E: Scattering
E: Scattering
Which of the following statements regarding the effect of frequency on Rayleigh scattering is TRUE? A: The amount of scattering is not affected by frequency. B: Scattering intensity doubles if frequency is doubled. C: Doubling the frequency results in halving the scattering intensity. D: Doubling the frequency results in quartering the scattering intensity. E: Scattering intensity is proportional to frequency raised to the fourth power.
E: Scattering intensity is proportional to frequency raised to the fourth power.
What system control on Doppler adjusts the PRF? A: Dynamic range B: Packet size C: Ensemble length D: Gain E: Spectral velocity scale
E: Spectral velocity scale
Bulk modulus is closely related to which of the following qualities? A: Attenuation B: Frequency C: Wavelength D: Volume E: Stiffness
E: Stiffness
Which of the following can NOT be evaluated with a tissue-equivalent phantom? A: Axial resolution B: Lateral resolution C: Contrast resolution D: Slice thickness E: Temporal resolution
E: Temporal resolution
Diagnostic ultrasound is limited in its diagnostic application to the adult brain because: A: The speed of sound in the brain is much faster than that in soft tissue resulting in a range artifact. B: Nearly all of the sound is transmitted at the interface between bone and soft tissue with no reflection to create an image. C: Diffraction of the sound beam occurs because of the irregular surface of the brain resulting in little transmission of sound through the cranial interface. D: Bending of the sound beam due to refraction results in a multipath artifact that distorts the image making it non diagnostic at high frequencies. E: The great acoustic impedance mismatch between the cranium and soft tissue causes most of the sound to be reflected at that interface.
E: The great acoustic impedance mismatch between the cranium and soft tissue causes most of the sound to be reflected at that interface.
With A-mode, the strength of the echo signal is represented by: A: The brightness of the dot B: The brightness of the spike C: The distance between two spikes D: The distance between two dots E: The height of the spike
E: The height of the spike
You are manipulating a volume data set that was previously obtained on your patient. What is the maximum number of imaging planes that can be obtained from this data set? A: One B: Ten C: One hundred D: One thousand E: There is no limit
E: There is no limit
These two images show a Pseudoaneurysm sac. In image A, the gray-scale echoes within the flow are visible and the color does not fill the aneurysm sac. What control was optimized in image B to allow the color to write over the gray-scale echoes? See images for question #513 A: PRF B: Wall filter C: Gain D: Packet size E: Threshold
E: Threshold
What technique would be most helpful in reducing grating lobes in your image? A: Beam steering B: Compound imaging C: 3D imaging D: Speckle reduction imaging E: Tissue harmonic imaging
E: Tissue harmonic imaging
What type of imaging results in selective reception of frequencies that are 2 times that of the transmitted frequency? A: Color Doppler imaging B: Pulsed Doppler imaging C: Tissue Doppler imaging D: M-mode imaging E: Tissue harmonic imaging
E: Tissue harmonic imaging
What component of the ultrasound system converts the electric energy provided by the Pulser into acoustic pulses transmitted into the patient? A: Receiver B: Scan converter C: Memory D: Display E: Transducer
E: Transducer
Which if the following does not affect the time required to create one image frame? A: Number of transmit focal zones B: Number of acoustic scan lines C: Image depth setting D: Speed of sound in tissue E: Transducer aperture
E: Transducer aperture
The transducer you are using is an array assembly. What is an advantage of this type of transducer? A: Transducer arrays produce pure, single-frequency beams B: Transducer arrays enable mechanical steering C: Transducer arrays produce very long pulses for improved axial resolution D: Transducer arrays have greater dynamic range, resulting in more displayed shades of gray E: Transducer arrays enable electronic focusing and steering
E: Transducer arrays enable electronic focusing and steering
When practicing universal precautions you should do all of the following EXCEPT: A: Wear gloves when there is a potential for contact with patient bodily fluids. B: Change gloves when moving from one patient to another. C: Wash hands immediately after gloves are removed. D: Wear face masks or eye protection whenever there is a possibility of blood splashing into your face. E: Wash gloves between exams for re-use from one patient to another.
E: Wash gloves between exams for RE-use from one patient to another.
What is the advantage of using Write zoom instead of Read zoom magnification? A: Write zoom always provides a higher frame rate than Read zoom B: Write zoom allows you to select a location in the image, whereas Read zoom must be applied to only the center of the image. C: Write zoom reduces the display of electronic noise and side lobes because it is performed in the memory component of the instrument D: Write zoom provides greater dynamic range than Read zoom E: Write zoom provides better spatial resolution than Read zoom
E: Write zoom provides better spatial resolution than Read zoom
With linear phased array transducers the outer crystals are excited ______ than the inner crystals.
Earlier
Determined by the medium through which the sound travels.
Echo arrival time
Involves use of the range equation with pulsed-wave imaging to determine reflector depth.
Echo ranging
A thin metallic barrier lining the inside of the case. This prevent spurious electrical signals in the air unrelated to diagnostic information from entering the transducer. Thus this helps prevent electrical noise from contaminating the clinically important electrical signals used to create diagnostic images.
Electrical shield
______ steering is not possible with annular arrays.
Electronic
Modern sequential linear array transducers perform both transmit and receive focusing using _________.
Electronic time delays
Beam steering is achieved _______ without any moving parts in the transducer.
Electronically
In modern linear sequential array transducers focusing is achieved _________.
Electronically
Linear arrays can steer sound beams _______.
Electronically
With linear phased array transducers sound beams are focused _______.
Electronically
The obvious advantage of phased array systems is the availability of ____________.
Electronically controlled adjustable focusing
In phased array transducers the ______ of the ultrasound system focus the sound beam.
Electronics
An array comprises a single slab of PZT cut into a collection of separate pieces called _______.
Elements
A measure of the beam width perpendicular to the imaging plane.
Elevational resolution
Caused by a lower attenuation within the structure than in the surrounding tissue.
Enhancement
Occurs distal to a structure that has less attenuation of the sound beam compared to the surrounding tissue.
Enhancement
Crystal damping ______ axial resolution.
Enhances
Mechanical transducers have only a single crystal therefore the _________ when the crystal malfunctions.
Entire image is lost
Whenever the crystal in any single crystal transducer breaks the __________.
Entire image is lost
Sound with frequencies above 1 MHz attenuate _______.
Entirely
With specular reflectors the angle of reflection is ____ to the angle of transmission.
Equal
For incidence to be normal, the angle must ________.
Equal 90 degrees
The frequency of sound emitted by a continuous wave probe is ______ the frequency of the electrical signal.
Equal to
Rayleigh scattering redirects the sound wave _____ in all directions.
Equally
A right angle is ______.
Exactly 90 degrees
Normal incidence means that the incident sound beam strikes the boundary at _____.
Exactly 90 degrees
A type of fixed focusing that uses an acoustic lens.
External focusing
Focusing with a lens
External focusing
Air has an ______ attenuation compared to soft tissue.
Extremely high
Attenuation in air is ______.
Extremely high
Attenuation is ______ in water.
Extremely low
The ratio of the focal length to the size of the aperture.
F-number
True or False: A pulsed ultrasound beam has the same intensity at different times during the pulse.
False
True or False: An ultrasound beam has the same intensity at different locations within the beam.
False
The region starting at the focus and extending deeper.
Far zone
Sound travels ______ in media with low density.
Faster
Both external and internal focusing are considered _______ techniques.
Fixed focusing
The distance from the transducer to the narrowest part of the beam.
Focal depth
The distance from the transducer to the focus.
Focal length
The focus is also known as the _____.
Focal point
A region around the focus where the beam is relatively narrow.
Focal zone
A region on either side of the focal point where the beam is relatively narrow and where image detail is superior.
Focal zone
Lateral resolution is good within the _______.
Focal zone
With annular phased array transducers the next larger crystal after the inner crystal is fired down the same scan line and information only from its ______ is stored.
Focal zone
Lateral resolution is best at the _____ where the beam is narrowest.
Focus
The location where the beam diameter is the narrowest.
Focus
The sound beam is _______ if the spike line is curved.
Focused
The primary method of improving lateral resolution is _____.
Focusing
____ improves lateral resolution by concentrating the sound energy into a narrower beam.
Focusing
Averages the data in pixels over successive frames.
Frame averaging
Temporal resolution is determined by the _____.
Frame rate
Term used to describe the far field.
Fraunhofer zone
Attenuation in soft tissue depends upon the waves ______.
Frequency
Describes the number of cycles that occur in one second.
Frequency
Determined by the propagation speed and the thickness of the piezoelectric material in the transducer and by the center frequency of the drive signal applied to the transducer.
Frequency
Determined by the sound source, not by the medium.
Frequency
The number of particular events that occur in a specific duration of time.
Frequency
The number of cycles that occurs in one second.
Frequency of a wave
Scattering is related to _________.
Frequency raised to the fourth power
The near zone length is also called the _______.
Fresnel zone
Secondary lobes off the main sound beam that occur with linear arrays and can produce significant artifacts in ultrasound images.
Grating lobes
These lobes are sound energy traveling from the transducer array in a direction different than the main beam.
Grating lobes
______ are the same as side lobes, but occur with array transducers.
Grating lobes
Determines the shades of gray that are assigned to incoming signal amplitudes.
Gray-scale map assignment
B-mode or B-scan is used to describe any form of _______.
Grayscale image
Attenuation is _____ in higher frequency sound than in lower frequency sound.
Greater
The PRF is reduced when systems image to a _____ depth.
Greater
The greater the pressure difference between two points, the ______ the flow rate.
Greater
Flow becomes turbulent at ______ Reynold's numbers.
High
Since the heart is a rapidly moving structure, ____ frame rates are required to assess it accurately.
High
When the depth of view is shallow, PRF is _____.
High
The wall filter is also known as ______.
High pass filter
The wall filter is also known as?
High pass filter
A method used to allow measurement of high velocities with pulsed Doppler while reducing aliasing.
High-PRF Doppler
A longer pulse has a _____ Q factor.
Higher
Attenuation in muscle is ______.
Higher
Shorter wavelengths are characteristics of _____ frequency sound.
Higher
Spatial peak intensity is always _____ than the spatial average intensity.
Higher
When the speed of sound in PZT is faster, the frequency of sound created by a pulsed wave transducer is ______.
Higher
When the system is imaging shallow the PRF is _____.
Higher
_____ frequencies improve both axial and lateral resolutions.
Higher
______ frequency transducers produce shorter wavelength sound, which in turn creates images of superior quality.
Higher
Attenuation in bone and lung is _______.
Higher than muscle
The goal in diagnostic imaging is to use the _______ that still provides images to the depth of the structures of clinical interest.
Highest frequency
States that a large active element may be thought of as millions of tiny, distinct sound sources.
Huygens principle
The apparent inconsistency between large and small sound sources and their beams is known as _______.
Huygens principle
The small sources of sound producing the V shaped wavelets are known as ______.
Huygens sources
What is the equation for IRC?
IRC (%) = [ Z2-Z1/Z2+Z1]2 x 100
The percentage of the sound beams intensity that passes through when the beam reaches a boundary between two media.
ITC
No reflection will occur if the two media have _______.
Identical impedances
The pulse repetition period is determined by the ______ that the sonographer selects.
Imaging depth
Determining the average intensity during the most intense half-cycle is a slightly different approach to measuring peak intensity in time and is called?
Imax or Im
The acoustic resistance to sound traveling in a medium.
Impedance
What is the equation for impedance?
Impedance (rayls) = Density (kg/m3) x propagation speed (m/s)
Larger diameter crystals ______ lateral resolution in the far field.
Improve
Axial resolution is ______ with wide-bandwidth transducers.
Improved
What is one of the main advantages of using tissue harmonics?
Improved contrast resolution
As the number of pixels increases, the spatial resolution of the image ______.
Improves
Higher frequency _____ lateral resolution in the far field.
Improves
A pair of waves are considered _____ when their peaks (maximum values) occur at the same time and at the same location. Similarly the troughs of the waves (minimum values) occur at the same time.
In-phase
At the boundary between two media if the reflected and transmitted intensities are added, the result must be the ______.
Incident intensity
The sound waves intensity immediately before it strikes a boundary.
Incident intensity
What is the equation for incident intensity?
Incident intensity = reflected intensity + transmitted intensity
With diffuse reflection the beam is weakened because of ______.
Incoherence
Lower frequencies have _____ penetration compared to higher frequencies.
Increased
As depth of view decreases, pulse repetition frequency ______.
Increases
As depth of view increases, pulse repetition period _______.
Increases
As materials become stiffer, the speed of sound in the material ______.
Increases
When power ____ so does amplitude.
Increases
When the PRF decreases the PRP _______.
Increases
Rayleigh scattering ______ with increasing frequency.
Increases dramatically
Axial resolution improves with _____ frequency.
Increasing
By ______ the sector width the user forces the system to fire more lines of sight for each imaging frame.
Increasing
Sound waves that have a frequency less than 20 Hz are defined as ______.
Infrasonic
Frequency less than 20Hz.
Infrasound
A beams power divided by its area.
Intensity
The concentration of energy in a sound beam.
Intensity
What is the equation for Intensity?
Intensity (W/cm2) = Power (w) / Area (cm2)
The percentage of the intensity that bounces back when a sound beam strikes the boundary between 2 media is the _______.
Intensity Reflection coefficient or IRC
Describes the fraction of sound transmitted at a boundary and the fraction of sound reflected at a boundary.
Intensity transmission coefficient
The percentage of ultrasound intensity that passes in the forward direction when the beam strikes an interface between two media is called the ________.
Intensity transmission coefficient or ITC
Both in-phase and out-of-phase wave pairs undergo ______.
Interference
More than one sound beam may travel in a medium and on occasion multiple beams may arrive at an identical location at exactly the same time. When the waves lose their individual characteristics and combine to form a single wave it is called _____.
Interference
Attenuation on soft tissue is ______.
Intermediate
A type of fixed focusing that uses a curved active element.
Internal focusing
Focusing with a curved active element
Internal focusing
_____ is the most common form of fixed focusing.
Internal focusing
Used to fill in the missing data betwee scan lines in both gray scale and color Doppler.
Interpolation
Crystal diameter and beam divergence are ______ related.
Inversely
Density and speed are _____ related.
Inversely
Duty factor is _____ related to imaging depth.
Inversely
Frequency and beam divergence are ______ related.
Inversely
PRF is _____ related to the maximum imaging depth.
Inversely
PRP and PRF are ______ related.
Inversely
PZT thickness and frequency are ______ related.
Inversely
Pulse repetition frequency and depth of view are _______ related.
Inversely
Pulse duration is ________ to the frequency.
Inversely proportional
Measures at the location where intensity is maximum, averaged over the transmit time (pulse duration)
Isppa
Measured at the location where intensity is maximum and averaged over all time, both the transmit and receive times.
Ispta
Measured at the location where intensity is maximum and at the instant in time that the most powerful part of the pulse passes.
Isptp
With _____ a parabolic flow profile may be seen.
Laminar flow
A _____ reflection will occur if the impedances are substantially different.
Large
Reflection is likely to occur when the dimension of the boundary is ______.
Large
The active elements in a convex array are much _________ than those found in a phased array.
Larger
The active elements in linear sequential arrays are much ______ than those found in linear phased arrays.
Larger
______ reflections occur with greater impedance differences.
Larger
The ability to distinctly identify two structures that are very close together when the structures are side by side or perpendicular to the sound beams main axis.
Lateral resolution
_____ answers the question: what is the minimum Distance that two structures positioned side by side can be apart and still produce two distinct echoes on an ultrasound image?
Lateral resolution
The ______ states that the sum of the percent of sound reflected and the percent of sound transmitted must equal 100%.
Law of conservation of energy
With deeper imaging, the listening time and the pulse repetition period _______.
Lengthen
With external focusing a _____ is placed in front of the piezoelectric material.
Lens
Higher frequency sound produces a beam with _____ divergence.
Less
Larger diameter crystals produce beams that diverge ______ in the car field.
Less
Larger transducer diameters produce a beam with _____ divergence.
Less
Lateral resolution is improved with higher frequencies because in the far field higher frequency pulses diverge ______ than low frequency ones.
Less
There is _____ penetration with higher frequencies.
Less
A pulse is short if there are few cycles in the pulse. This is known as _______.
Less ringing
If speed 2 is less than speed 1 the transmission angle will be ______ the incident angle.
Less than
The numerical value for axial resolution is _______ the value for lateral resolution.
Less than
The transmission angle will be less than the incident angle when the speed of Medium 2 is ______ the speed of Medium 1.
Less than
A number in scientific notation form with a negative exponent has a value ______.
Less than 1
Duty factors for imaging systems must always be ______.
Less than 100%
If the frequency of a sound wave is _______ it is below the threshold of human hearing and cannot be heard.
Less than 20 Hz
An array transducer where the active elements are arranged in a straight line.
Linear array
Only the ______ transducer has the same line density for both the near and far field.
Linear array
A novel method of rating numbers.
Logarithm
A decibel scale is _______.
Logarithmic
Decibel notation is _______.
Logarithmic
Decibels are based on a mathematical construct called ______.
Logarithms
When the depth of view is deep, the PRP is _____.
Long
In general, color Doppler uses a _____ pulse length compared to B-mode imaging to compensate for the lower reflectivity of red bold cells compared to tissue.
Longer
The lower the frequency the ______ the wavelength.
Longer
When a reflector is located deep the time from pulse creation to reception is ______.
Longer
When the system is imaging more deeply, the time from one pulse to the next is ______.
Longer
In a _____ particles move in the same direction that the wave propagates.
Longitudinal wave
Attenuation in blood, urine, and biologic fluids is ______.
Low
Attenuation in fat is _____.
Low
When the depth of view is deep, PRF is ______.
Low
Transducers used for diagnostic ultrasound are _____ transducers.
Low-Q
Because imaging probes use backing material and have a wide bandwidth they are often referred to as ______.
Low-q
A shorter pulse has a ____ Q factor.
Lower
The disadvantage of diffuse reflections is that back scattered signals have a ______ strength than Specular reflections.
Lower
When the system is imaging deeper, the PRF is ______.
Lower
____-mode is the only mode that provides information about a reflectors changing location with respect to time.
M
Appear as a group of horizontal wavy lines.
M-modes
A successful method of obtaining a 3D data set and is based on a six degree-of-freedom magnetic field sensor. A transmitter produces a magnetic field and the sensor (on the transducer) receives the signal allowing the position and angulation of the transducer to be tracked (within the field).
Magnetic field tracking
Used to adjust the amplification of all of the reflected signals, not just those at a specific depth.
Master gain
Positioned in front of the PZT at the face of the transducer
Matching layer
Pulse repetition frequency is determined by the ________.
Maximum imaging depth of the system
The strength of a sound beam varies depending on the _______.
Measurement point within the beam
Annular phased array transducers use ______ steering.
Mechanical
The point of ______ determines the slice thickness in linear array.
Mechanical focus
In a mechanical transducer the scan plane is created through _______.
Mechanical steering
Smaller diameter crystals produce beams that spread out or diverge ______ in the deep far zone.
More
Reflections arising from the focal zone create images that are ______ than those from other depths.
More accurate
Higher frequencies are absorbed _____ than lower frequencies.
More quickly
As a result of absorption, higher frequency waves attenuate ______ lower frequency waves.
More than
Higher frequency sound beams scatter _____ than lower frequency beams.
Much more
Annular phased arrays are also known as _______.
Multi-focus
A _____ is created when the sound beam bounces off of one or more reflectors before it encounters a reflector that redirects it back to the transducer.
Multipath artifact
Generally modern transducers called arrays contain _____ active elements.
Multiple
During reception when reflected sound arrives at the transducer _____________ are excited.
Multiple elements along the front of the probe
High frequency sound beams are ______ than low frequency beams.
Narrower
With lateral resolution _____ beams have better resolution.
Narrower
At the focal point the beam width is ______.
Narrowest
The beam gradually _____ within the near zone.
Narrows
The region from the transducer to the focus.
Near zone
Can the sonographer change the pulse duration?
No
Is axial resolution adjustable?
No
Is propagation speed adjustable?
No
Is spatial pulse length adjustable?
No
Is the frequency adjustable?
No
Is the pulse duration adjustable?
No
Is wavelength adjustable?
No
Occurs when the interface is small, less than several wavelengths across.
Nonspecular reflection or scattering
Indicates a 90 degree angle of incidence.
Normal incidence
Occurs when the sound beam strikes the interface at a 90 degree angle.
Normal or perpendicular incidence
If something other than pressure, density, or distance (particle motion) rhythmically oscillates in a wave, then the wave is _____.
Not a sound wave
Speed is _____ by the nature of the sound wave.
Not affected
For incidence to be oblique the angle must _______.
Not equal 90 degrees
The z-axis in a-mode represents?
Nothing
The z-axis in b-mode represents?
Nothing
Acute angles are _____.
Oblique
In a mechanical transducer the minimum number of active elements is?
One
The thickness of the PZT crystal in a pulsed wave transducer is equal to ___________.
One-half of the wavelength of sound in the PZT
The matching layer is ______ thick.
One-quarter wavelength
When one ring of an annular phased array transducer malfunctions __________ image is lost.
Only a portion of the
Speed is determined by?
Only by the medium through which the sound is traveling
Pulse repetition frequency is determined ________.
Only by the sound source
Pulse average intensity (Ipa) is averaged _________.
Only during the pulse duration (on time only)
At the beginning of the far zone the beam is __________.
Only one half as wide as it is at the transducer
At the end of the near zone the beam narrows to ________.
Only one half the width of the active element
When two reflectors are closer side by side than the beam width _______ is observed on the image.
Only one reflection
When one element in a linear sequential array is damaged _________________ is affected.
Only the portion of the image extending directly below the damaged element
When one element in a linear sequential array transducer is damaged ____________ are affected.
Only the scan lines that would have been created by the defective crystal
A-mode is used extensively in _______.
Ophthalmology
Sound waves are identified by _____ in _____ variables.
Oscillation Acoustic
When two waves are _____ their peaks occur at different times, and so do their troughs.
Out-of-phase
Amplifies signals from all depths equally and does not compensate for attenuation changes at specific depths.
Overall receiver gain or master gain
Because the PRF sets the Nyquist limit (1/2 PRF), higher velocities can be measured without aliasing by increasing the ______.
PRF
The only factor that is useful in determining the point of aliasing (Nyquist limit) is the ______.
PRF
What sets the Nyquist limit?
PRF
What is the equation for PRF?
PRF (Hz) = 77,000 cm/s / imaging depth (cm)
When a sonographer adjusts a systems maximum imaging depth, the ______ is altered.
PRP
What is the equation for PRP?
PRP (,us) = Imaging depth (cm) x 13 ,us/cm
The piezoelectric crystal itself. In a simple probe this is shaped like a coin. The characteristics of the sound beam emitted by the transducer are related to the dimensions of this.
PZT or Active Element
Name in decreasing order of impedance PZT to Skin.
PZT>Matching layer>Gel>Skin
The ______ indicates the number of pulses transmitted on each scan line in the color image.
Packet size
Axial resolution measures the ability of a system to display two structures that are very close together when the structures are ______.
Parallel to the sound beams main axis
The features of a sound wave are called ______.
Parameters
Occurs when the slice thickness is wider than the structure being imaged.
Partial volume artifact
The acoustic variable pressure is measured in units of?
Pascals or Pa
The difference between the maximum and minimum values of an acoustic variable.
Peak-to-peak amplitude
The inverse of the frequency.
Period
The time it takes a wave to vibrate a single cycle, or the time from the start of a cycle to the start of the next cycle.
Period
Normal incidence is also known as?
Perpendicular incidence
Frame averaging is also known as?
Persistence
Focusing with the electronics of the ultrasound system
Phased array focusing
A _______ has a small surface area with a flat face.
Phased array transducer
With ______ all of the elements are fired as one group but with very small time delays to steer the beam.
Phased array transducers
For a linear phased array transducer the beam is steered and focused using an electrical technique called _______.
Phasing
With linear phased array transducers the two dimensional image is built up with an electronic steering process called _______.
Phasing
What does PACS stand for?
Picture Archive and Communication System
Describes the property of certain materials to create a voltage when they are mechanically deformed.
Piezoelectric effect
A process that creates materials by exposing the material to a strong electrical field while being heated to a substantial temperature.
Polarization
When the Doppler ultrasound beam intersects a vessel in which the blood is flowing toward the Doppler beam, the frequency of the reflected signal is higher than that of the transmitted signal. This is termed ______.
Positive frequency shift
The rate of energy transfer or the rate at which work is performed.
Power
If the amplitude of a wave is increased by a factor of 3, how has the power changed?
Power = Amplitude ^2 = 3^2 (3x3) = 9
_____ differences drive flow.
Pressure
A sound wave is a _____.
Pressure wave
The distance that a sound wave travels through a medium in 1 second.
Propagation speed
Axial resolution is _____ to pulse length.
Proportional
Intensity is _____ to power.
Proportional
The height of the upward deflection is _______ the amplitude of the returning echo.
Proportional to
A ______ of ultrasound is a collection of cycles that travel together.
Pulse
Refers to the transmit time only (pulse duration).
Pulse
The number of electric pulses delivered to the active element per second.
Pulse Repetition Frequency
Taking the average intensity during the pulse duration (transmit time).
Pulse average intensity or Ipa
The average intensity during the pulse duration only.
Pulse average intensity, or Ipa
Axial resolution is related to______.
Pulse duration
The actual time from the start of a pulse to the end of a pulse. A single transmit, talking, or on time.
Pulse duration
The length of time required to complete one pulse.
Pulse duration
The time it takes to complete one pulse.
Pulse duration
The time that a pulse is on and is typically measured in microseconds.
Pulse duration
The time that it takes the train to roll past us at a railroad crossing would be considered the ______.
Pulse duration
The transmit time is called the _______.
Pulse duration
What is the equation for pulse duration?
Pulse duration (,us) = # of cycles x period (,us) or Pulse duration (,us) = # of cycles/Frequency (MHz)
An effective method to filter out the fundamental frequency (transmitted frequency) and leave only the harmonic frequencies for display.
Pulse inversion harmonics
The distance of the pulse end to end typically measured in mm.
Pulse length
The number of pulses emitted by the transducer in one second.
Pulse repetition frequency
The number of pulses that an ultrasound system transmits into the body each second.
Pulse repetition frequency
The number of pulses that occur in one second.
Pulse repetition frequency
The time between the pulses.
Pulse repetition period
The time from the start of one pulse to the start of the next pulse. It includes one pulse duration plus one listening time.
Pulse repetition period
Determines the depth of origin of reflected echoes by use of the range equation.
Pulsed wave ultrasound
The ____ produces the electric voltage pulses to the beam former and on to the transducer.
Pulser
A Unitless number that is related to bandwidth.
Quality factor
What is the equation for quality factor?
Quality factor = main frequency/bandwidth
Red, green, and blue are referred to as the ____.
RGB signal
Variance maps should not be confused with ______, which contain some green adjacent to the blue color.
Rainbow maps
The ability to determine the depth from which an echo has arrived.
Range resolution
Low-pressure regions are _____.
Rarefactions
An object that is much smaller than the wavelength of the sound beam.
Rayleigh scatterer
Red blood cells are considered _______ because they are smaller than the wavelength of the sound beam.
Rayleigh scatterers
A special form of scattering that occurs when the structures dimensions are much smaller than the beams wavelength.
Rayleigh scattering
When interaction is organized, the sound in all directions is ________.
Rayleigh scattering
What is the equation for acoustic impedance?
Rayls = Density x Speed of Sound
Differences in impedance result in ________.
Reflection at boundaries
Determined by measuring the elapsed time between the transmitted pulse and the reception of the echo.
Reflector depth
Results in the bending of the beam.
Refraction
_____ of the sound beam occurs whenever there is both oblique incidence and a difference in media propagation speeds.
Refraction
The edge shadowing seen with curved interfaces is caused by?
Refraction of the sound beam.
Used to eliminate weak echo signals from the display.
Reject control
Two items that are associated or affiliated. However, the relationship between the items does not have to be specified.
Related or Proportional
The ability to image accurately.
Resolution
Piezoelectric materials change shape when a voltage is applied to them, a process called ______.
Reverse piezoelectric effect
The _____ describes the point at which flow becomes turbulent.
Reynold's number
What is the equation for the Reynold's number?
Reynold's number = Average Flow Speed x Tube Diameter x Density
The stacking up of red blood cells that occurs at low velocities and low shear rates.
Rouleaux formation
A standard pattern for evaluation of monitors and cameras.
SMPTE test pattern
The beam uniformity coefficient is also known as _______.
SP/SA Factor
______ intensity is the most relevant intensity with respect to tissue heating.
SPTA
All sound, regardless of the frequency, travels at the ______ through any specific medium.
Same speed
The digital memory of the ultrasound system.
Scan converter
Occurs when the sound strikes an irregular or rough surface that is small compared to the wavelength.
Scattering
The random redirection of sound in many directions.
Scattering
When interaction is disorganized, sound in all directions is ______.
Scattering
The PRF is high when systems image only to a ______ depth.
Shallow
With linear phased arrays the sound beam created by this more curved electrical pattern will have a _______ focus.
Shallower
A pulse is short if each cycle in the pulse has a ____ wavelength.
Short
Short duration pulses also have a _____ length.
Short
When a reflector is located superficially, the time from pulse creation to reception is ______.
Short
When the depth of view is shallow, PRP is ______.
Short
When the system is imaging at shallow depths, the time from one pulse to the next is ______.
Short
With shallow imaging the listening time and the pulse repetition period ______.
Shorten
Axial resolution is improved with higher frequencies because of the ______ pulses associated with high frequency sound.
Shorter
Lower numerical values of axial resolution indicate a ______ pulse.
Shorter
The _____ the pulse duration, the better the axial resolution.
Shorter
_____ wavelength sound usually produces higher quality images with greater detail.
Shorter
______ duration pulses are desirable for imaging because they create images of greater accuracy.
Shorter
______ pulses are desirable because they create more accurate images.
Shorter
Part of the beam pattern from any transducer.
Side lobes
What is the equation for Snell's Law?
Sin (transmission angle)/Sin (incident angle) = Speed of Medium 2/ Speed of Medium 1
A Unitless number with a value from 0 to 1.
Sine
Elevational resolution is determined by ______.
Slice thickness
What is another term for elevational resolution?
Slice thickness
Partial volume artifact is also known as ______.
Slide thickness artifact
Beam formers of phased array systems steer sound beams by introducing ____________ in the electrical excitation spikes of the elements creating the beam.
Slope-shaped delays
A _____ reflection will occur if the impedances are slightly different.
Small
Sound scatters when the tissue interface is _______.
Small
In the far zone higher frequencies result in ______ beam diameters.
Smaller
With lateral resolution _____ numbers are preferable since they indicate more accurate images.
Smaller
The diameter of a sound beam is ______ at the end of the near zone.
Smallest
Dictates the angle of transmission that will occur at an interface with refraction of the sound beam.
Snell's Law
Relates the angle of transmission of the sound beam to the relative velocities of sound in the two media.
Snell's Law
In convex sequential arrays ________ of the crystals are fired simultaneously to create a single sound beam.
Some but not all
With linear sequential array transducers ____________ to create each sound wave.
Some but not all of the crystals are fired simultaneously
Duty factor is determined by?
Sound source only
Period is determined by the ______.
Sound source only
If one of the three acoustic variables has a rhythmic oscillation, then the wave is a ______.
Sound wave
The _____ of a sound wave is the ultrasound system and transducer.
Source
Spatial peak intensity (Isp) is the maximum in ______.
Space
Refers to distance or space.
Spatial
What does SPPA stand for?
Spatial peak, pulse average
What does SPTA stand for?
Spatial peak, temporal average
Axial resolution is determined by the ______.
Spatial pulse length
The distance from the front tip of our imaginary train to the end of the caboose.
Spatial pulse length
The distance that a pulse occupies in space from the start to the end of a pulse.
Spatial pulse length
The length of the train from the beginning of the locomotive to the end of the caboose would be considered the _______.
Spatial pulse length
A broadening of the spectrum of frequencies reflected back to the transducer.
Spectral broadening
The area underneath the systolic peak on the Doppler waveform that is absent of echoes.
Spectral window
When interaction is organized, the sound back to the transducer is ______.
Specular
When the boundary is smooth, the sound is reflected in only one direction in an organized manner. This reflection is called ______.
Specular
_____ reflection occurs when a light wave strikes a mirror.
Specular
One method of decreasing grating lobes during the manufacturing process of ultrasound transducers is to use a method called _____.
Subdicing
A method employed to reduce the presence of noise in the system.
System shielding
A method of increasing amplification applied to echo signals arising from deeper structures to account for the weakening (attenuation) of the sound beam with depth.
TGC
Used to amplify echo signals from deeper structures which have undergone greater amounts of attenuation more than echo signals from shallow structures.
TGC
Used to amplify echoes from deeper structures so that they appear as bright as similar structures located at more shallow depths.
TGC
Refers to all time, transmit (pulse duration), and receive.
Temporal
Averaging the intensity during the entire PRP (both the transmit and receive times).
Temporal average intensity or Ita
Measuring the intensity of the beam at the instant in time of its maximal value.
Temporal peak intensity or Itp
The highest temporal intensity is the _______.
Temporal peak or Itp
What is another name for pulse duration?
Temporal pulse length
Related to the amount of time it takes to complete a single frame of information.
Temporal resolution
What does HIPAA stand for?
The Health Insurance Portability and Accountability Act
Temporal average intensity (Ita) is averaged during _______.
The PRP (both on and off times)
Conversion of a sound wave to an electric signal occurs when the sound wave strikes the transducer surface and is termed ______.
The Piezoelectric effect
What does SMPTE stand for?
The Society of Motion Picture and Television Engineers
Spatial average intensity (Isa) is averaged over _______.
The cross-sectional area of the beam
Refection of an ultrasound wave depends upon __________.
The difference in acoustic impedances of the two media at a boundary
The percentage of the incident beam that is reflected is related to ________.
The difference in the impedances of the tissues
Impedance is a characteristic of ______.
The medium only
M-mode has been used primarily to assess __________.
The motion of cardiac walls and structures
With linear phased array transducers ________ of the electrical signals from the ultrasound system determine the sound beams direction and focus.
The overall pattern
When the beam is two near zone lengths from the transducer the beam is ______ as the active element.
The same size
Who controls the depth of view?
The sonographer
The pulse duration is determined by?
The sound source only
The pulse repetition period is determined by?
The sound source only
Frequency of a sound wave is determined by the ______.
The source only
Speed changes only when ________.
The wave travels from one medium to a different medium.
Lower frequency sound results in a _______ half-value layer.
Thick
The half-value layer is _____ for tissues that attenuate sound a little, such as fluids.
Thicker
Higher frequency sound results in a ____ half-value layer.
Thin
The half-value layer is ______ for tissues that attenuate sound a great deal such as lung or bone.
Thin
For pulsed wave transducers _____ active elements create higher frequency sound pulses.
Thinner
The ____ the beam, the more accurately a structure can be imaged without interference from surrounding tissue.
Thinner
The crystal or element must be _____ for higher frequencies
Thinner
Used to reduce the display of weak echo signals that most likely arise from electronic noise.
Threshold
What is another name for reject control?
Threshold
A ______ has elements arranged in a linear fashion on a tightly curved radius.
Tightly curved array
Pulse repetition period is reported in units of?
Time
Temporal peak intensity (Itp) is maximum in _____.
Time
The term temporal refers to?
Time
The x-axis in m-mode represents?
Time
The x-axis of an M-mode display represents ______.
Time
The PRP is the ______ of a sound pulse between the transducer and the bottom if the image.
Time-of-flight
In ______, the receiver selectively "listens" to the harmonic frequencies that were generated as the sound traveled through the tissue.
Tissue harmonic imaging
A new method of ultrasound imaging in which the harmonic of the transmitted frequency is used to create the image.
Tissue harmonics
What is the equation for total attenuation?
Total attenuation (dB) = attenuation coefficient (dB/cm) x distance (cm)
The Doppler frequency is determined by the ______.
Transducer
The function of the ____ is to convert electric energy into mechanical vibrations (sound energy) for transmission into the patient.
Transducer
Critical to ultrasounds ability to image structures located deep in the body.
Transmission
During ______ electrical energy from the system is converted into sound.
Transmission
Refraction is ________.
Transmission with a bend
The intensity of the portion of the incident beam that, after striking a boundary, continues forward in the same general direction that it was traveling.
Transmitted intensity
In a ______ particles move in a direction that is perpendicular (at right angles) to the direction that the wave propagates.
Transverse wave
Particle motion that is perpendicular to the direction of propagation characterizes a ______.
Transverse wave
T or F: Increasing frequency does not increase exposure.
True
Distal to a stenosis, flow becomes _____.
Turbulent
Spectral broadening is associated with _______.
Turbulent flow
Peak-to-peak amplitude is _____ the value of the amplitude.
Twice
Since a pulse travels to the reflector and back to the transducer, the total distance that a pulse travels is _____ the reflector depth.
Twice
When one reflector is twice as deep as another reflector, the pulses time-of-flight is _______ for the deeper reflector.
Twice as long
Since decibels are always comparisons ______ are required to use decibels.
Two intensities
A frequency that is 20,000 Hz or higher is termed _____ and humans cannot hear it.
Ultrasonic
Frequency greater than 20kHz.
Ultrasound
The sound beam is ______ if the spike line is straight.
Unfocused
When the spike line is straight an ______ sound beam is created.
Unfocused
A number followed by the word percent is ______.
Unitless
Pulse duration is reported in?
Units of time
PRF is ______ to frequency.
Unrelated
Two items that are not associated.
Unrelated
Sound waves produced by very small sources diverge in the shape of a _____.
V
_____ maps have a green shade that is used to indicate turbulence.
Variance
Rainbow maps are commonly used in ____ scanning.
Vascular
Indicates the speed or swiftness of a fluid moving from one location to another.
Velocity
All intensities have units of _____.
W/cm2
All intensities have units of?
W/cm2
Intensities are reported with units of?
W/cm2
The units of intensity are?
W/cm2 or Watts from power and cm2 from beam area
A focus can be considered the _____ of a sound beam.
Waist
Flash artifact can be reduced on the display by increasing the ______.
Wall filter
High pass filter is also called a _______.
Wall filter
The ______ is used to eliminate frequency shifts below a set threshold from the display.
Wall filter
Used to eliminate frequency shifts below a set threshold from the display.
Wall filter
No noticeable attenuation of ultrasound of frequencies less than 10 MHz is observed in ______.
Water
Power has units of _____.
Watts
What are the units for intensity?
Watts/m2
The distance of length of one complete cycle.
Wavelength
The only acoustic parameter that is determined by both the source and the medium.
Wavelength
How do you find the wavelength of a sound wave in soft tissue?
Wavelength (mm) = 1.54 mm/,us / frequency (MHz)
Wavelength is determined by what equation?
Wavelength= propagation speed/Frequency
Sound _____ as it propagates.
Weakens
Can the sonographer alter the listening time?
Yes
Is intensity adjustable?
Yes
Is power adjustable?
Yes
Is the amplitude adjustable?
Yes
Is the duty factor adjustable?
Yes
Is the pulse repetition frequency adjustable?
Yes
Is the pulse repetition period adjustable?
Yes
What is required for reflection with oblique incidence?
You cannot predict what is required it is too complex
The axis that runs across the width of the transducer.
Z axis
When displayed on a CRT the amplitude information of a B-mode is routed into the ______.
Z-axis
Unlike linear sequential arrays the sound beams transmitted from a convex array _________ to each other.
are not parallel
Sound ____ travel through a vacuum.
cannot
The acoustic variable distance is measured in units of?
cm or mm
Molecules in a wave are _____, or squeezed together.
compressed
Frequency is reported in units of ______.
cycles per second/MHz
What are the units of the attenuation coefficient?
dB/cm
Refraction ______ with perpendicular incidence.
does not occur
The acoustic variable density is measured in units of?
kg/cm3
The intensity of a sound beam varies depending on the _______.
location of the measurement
Sound must travel through a ______, where molecules are alternately ______ and _______.
medium compressed rarefied
Imax (Im) intensity is averaged over the _________.
most intense half-cycle
Molecules in a wave are _____, or stretched apart.
rarefied
Sound travels in a _____ line.
straight