Practice exam
If the gain of an amplifier is 18 dB, what is the new gain if the power is reduced by half? a. 15 dB b. 9 dB c. 36 dB d. 0.5 dB
15 dB
If sound travels through a large quantity of water and then encounters a reflector, the reflector will appear to be: a. too far away b. too close c. in the correct location d. not enough info to tell
A
If the _____ is increased, the flow increases a. pressure differential b. resistance c. length of vessel d. viscosity of blood
A
When a patient stands up, what is the hydrostatic pressure at the ankles? a. 100 mmHg b. 50 mmHg c. 0 mmHg d. 140 mmHg
A
Which of the following statements is true about a single pulse of ultrasound from a transducer? a. it contains a range of frequencies b. it contains sound at the resonant frequency of the transducer only c. the shorter the pulse, the narrower the bandwidth d. sound energy is continuously transmitted
A
What is the reflected intensity from a boundary between two materials if the incident intensity is 1mW/cm^2 and the impedances are 25 and 75? a. 0.25 mW/cm^2 b. 0.33 ^ c. 0.05 ^ d. 1.0 ^
A.
Which of the following describes Snell's Law? a. law that describes the angle of a transmitted beam b. law that describes the impedance of two media c. law that describes the intensity of a reflected beam d. law that says you have to buckle up
A.
Which physics principle describes the decrease in pressure at a stenosis due to increase velocity at the site? a. Bernoulli Principle b. snell's law c. Poiseuille's Law d. Doppler principle
A.
While scanning the posterior tibial artery, a mirror image of the arterial signal appears on opposite side of the Doppler baseline. All of the following could assist in correcting the issue, EXCEPT: a. use a same approach and incident angle but use a CW imaging probe b. try a new window that offers more space between tibial bone and the artery c. try a new window where the vessel course is less perpendicular to the probe d. turn down Doppler gain
A.
diffraction refers to: a. spreading out of the ultrasound beam b. conversion of sound to heat c. reflection of the beam at an interface d. bending of the sound beam crossing a boundary
A.
Approximately what percent of the incident intensity is reflected at a soft tissue-air interface? a. 100% b. 50%-75% c. <20 % d. 0 %
A. 100 %
The reason most ultrasound systems are calibrated at 1540 meters per second is because: a. 1540 meters per second is the average speed of sound encountered in the patient b. 1540 meters per second is the maximum speed of sound encountered in a patient c. 1540 meters per second is the speed of sound in muscle d. 1540 meters per second is the minimum speed of sound in a patient
A. 1540 meters per second is the average speed f sound encountered in the patient
An increase in PRF would lead to: a. An increase in PD b. a decrease in PD c. An increase in the number of cycles d. A decrease in resolution
A. An increase in PD
Blood flow volume changes in the body are mainly controlled by what two factors? a. cardiac function and peripheral resistance b. Viscosity and friction c. cardiac function and vessel radius d. vessel radius and resistance
A. Cardiac function and peripheral resistance
Which of the following would improve temporal resolution on color Doppler? a. decrease sample size b. increase color gain c. steer the sample box d. increase wall filter
A. Decrease sample size
What system control can reduce the appearance of clutter on an image? a. decreasing color priority b. increasing color threshold c. increasing persistance d. decreasing color scale
A. Decreasing color priority
The direction of the Doppler shift determines the : a. Color Doppler hue b. Peak velocity of the flow c. average velocity of flow d. color Doppler Luminance
A. Hue
What time is defined as the beginning of one pulse to the beginning of the next pulse and therefore includes both the "on" and "off" time? a. PRP b. PD c. DF d. PRF
A. PRP
What statement is most correct about power? a. Power is the rate of work b. power is expressed as mW/cm^2 c. power and intensity are always the same d. power is equal to the transfer of energy
A. Power is the rate of work
Which of the following transducers can be described as having the scan lines originate from a common point of origin? a. sector array b. vector array c. curvilinear array d. linear sequential array
A. Sector array
As frequency increases: a. a three- cycle ultrasound pulse decreases in length b. wavelength increases c. attenuation decreases d. propagation speed increases
A. a three-cycle ultrasound pulse decreases in length
Information that travels to the scan converter from the receiver is initially in what format? a. analog b. digital c. binary d. Hexadecimal
A. analog
if the line density changes but the imaging depth remains the same, what else much change? a. frame rate b. PRP c. PRF d. Resolution
A. frame rate
If blood pressure is increased with no change in resistance, what happens? a. increased flow rate b. increased viscosity c. decreased flow volume d. decreased flow rate
A. increased flow rate
Which of the following controls will reduce the low level echoes demonstrated on the Doppler image? a. increased wall filter settings b. increased the Doppler gain c. drop the baseline d. increased compression
A. increased wall filter settings
Density and propagation speed are: a. Inversely related b. Directly related c. directly proportional d. unrelated
A. inversely related
At which point do the amplitudes get assigned gray scale numbers so they can be placed into memory? a. pre-processing of the signal b. post-processing of the signal c. in the computer memory d. in the receiver
A. preprocessing of the signal
If the ____ is increased, flow increases: a. pressure difference b. resistance c. length of vessel d. A&B
A. pressure difference
side lobe artifacts results from which of the following: a. sound beams bending b. linear array transducer architecture b. increased attenuation in the far field d. acoustic energy radiating in a different direction other than the beam's main axis
A. sound beams bending
What happens to a digital image when the pixel density is increased? a. there is more spatial detail b. the temporal resolution increases c. the larger the field of view d. there are more shades of gray
A. there is more spatial detail
In the most common type of transducers, the slice-thickness plane is focused: a. using a lens b. using a matrix array c. electronically d. using 2D technology
A. using a lens
What is the definition of the beam uniformity ratio? a. The spatial intensity divided by the temporal intensity b. the spatial peak intensity divided by the spatial average intensity c. the temporal average intensity divided by the spatial average intensity d. the temporal peak intensity divided by the spatial peak intensity
B
Which law describes the relationship between flow and the pressure differential, viscosity, and length? a. Bernoulli's Law b. Poiseuille's law c. Snell's Law d. Doppler's law
B
Which of the following is true about Color Doppler? a. Each pixel can be both color and grayscale at the same time b. each pixel can be either grayscale or color c. Pixels cannot be colorized d. the gain determines the color priority of the pixels
B
a video display that is limited to only black and white, with no other shades of gray is called: a. binary b. monochrome c. bistable d. unichrome
B
Ultrasound attenuates an average of _____ dB/cm of travel for each megahertz of frequency a. 1 b. 0.7 c. 0.33 d. 0.25
B 0.7
The typical range of frequency for diagnostic ultrasound imaging is: a. 20-20,000 HZ b. 1 to 20 MHz c. 2- 15 kHz d. 12-100mHz
B 1-20 MHz
If the amplitude is decreased by 50%, what is the corresponding change in power? a. 3 dB b. -6 dB c. -3 dB d. 0 dB
B. -6 dB
which of the following is in the range of infrasound? a. 1.5 kHz b. 15 Hz c. 25 Hz d 1 MHz
B. 15 Hz
Which of the following is in the range of audible sound? a. 15 Hz b. 18 kHz c. 25,000 Hz d. 2 Hz
B. 18 kHz
If the peak systolic velocity is 3 m/s, what is the peak pressure gradient ? a. 9mmHg b. 36 mmHg c. 27 mmHg d. 18 mmHg
B. 36 Bernoulli's equation: pressure gradient = 4(velocity)^2 4 (3)(3)=36
Which of the following has the highest relative attenuation? a. bone b. air c. liver d. blood
B. Air
Venous blood flow in the legs is propelled toward the heart by: a. Respiration only b. muscle contraction and respiration c. cardiac pulsatility, muscle contraction, and respiration d. cardiac pulsatility only
B. Muscle contraction and respiration
Changing the color flow Doppler scale alters the: a. Doppler shift b. PRF c. sample volume size d. packet size
B. PRF increase in scale = increase in PRF Decrease in scale = decrease in PRF
The phenomenon that occurs when the beam strikes a small reflector with a diameter of less than the sound wavelength is referred to as: a. specular reflections b. Rayleigh scattering c. Snell's scattering d. none of the above
B. Rayleigh scattering
All of the following are advantages of CW Doppler over PW Doppler except: a. No aliasing b. ability to determine high velocities at exact locations c. not limited by PRF d. ability to evaluate deeper vessels
B. ability to determine high velocities at exact locations
____ compares each reflected echo to the same echo from a previous US pulse to determine if motion is present a. quadrature dector b. autocorrelation c. temporal resolution d. registration accuracy
B. autocorrelation
All of the following are limitations of analog Doppler, except? a. unable to detect post stenotic turbulance and spectral broadening b. cannot detect flow velocities over 250 cm/s c. underestimates high velocities and overestimates low velocities d. cannot detect flow less than 6 cm/s
B. cannot detect flow velocities over 250 cm/s
The attenuation coefficient is expressed in: a. mW/cm^2 b. dB/cm/ MHz c. dB d.MHz/cm
B. dB/cm/ MHz
The "useful" artifact that one might see behind a weakly attenuating structure: a. shadowing b. enhancement c. reflection d. refraction
B. enhancement
Which of the following is displayed on the y axis of a Doppler tracing? a. time b. frequency shift c. speed d. motion
B. frequency shift
The Doppler tracing of the flow in a vessel just distal to a stenosis will demonstrate ____ than at the site of stenosis a. More laminar flow b. greater bandwidth c. greater resistance d. greater Doppler shift
B. greater bandwidth
Which of the following will increase the risk of aliasing? a. Decreasing the image depth b. increasing the transmit frequency c. low velocity blood flow d. intercept angle of 90 degree
B. increasing the transmit frequency
If the intensity of a signal is doubled, what is the affect on amplitude? a. halved b. quadrupled c. doubled d. squared
B. quadrupled
In soft tissue ____ makes imaging less angle dependent: a. refraction b. scattering c. absorption
B. scattering
What term indicates the phenomenon of a PW Doppler tracing displaying a wider distribution of the velocity blood cells with varying degrees of arterial blockage? a. turbulance b. spectral broadening c. laminar flow d. occulsion
B. spectral broadening
The spatial resolution capabilities of the system are primarily functions of the : a. pulser b. transducer c. receiver d. display
B. transducer
Which of the following correctly describes a normal Doppler waveform of an artery from the lower extremity? a. There will be a low resistance, monophasic waveform with a small amount of flow reversal in diastole b. the triphasic waveform will have 2 components of antegrade flow during the cardiac cycle c. the triphasic waveform will have 2 components of normal retrograde flow during the cardiac cycle d. the triphasic waveform never demonstrates a retrograde flow component during the cardiac cycle
B.the triphasic waveform will have 2 components of antegrade flow during the cardiac cycle
All of the following correctly describe a CW Doppler evaluation except: a. will not demonstrate a spectral window b. contains at least 2 elements, one that transmits sound and one that receives it c. The angle of incidence does not affect the velocity evaluation using CW Doppler because you are not evaluating the vessel at a specific depth d. CW Doppler is most useful with high velocities
C
Which of the following is best defined as the ability to discriminate between two closely spaced reflectors? a. Temporal resolution b. Range accuracy c. Spatial resolution d. Amplification
C
Which of the following would most likely decrease beam divergence in the far field? a. large crystal diameter, low frequency b. small crystal diameter, low frequency c. large crystal diameter, high frequency d. Small crystal diameter, high frequency
C
Which of the following is a limitation of the Fast Fourier Transformation? a. cannot process more than 2 samples per cycle b. cannot correctly process a frequency shift that is less than one half of the PRF c. requires a minimum of 2 samples per cycle to process and produce a Doppler tracing d. cannot correctly process a frequency shift that is less than half transducer frequency
C.
Which of the following would create an increase in Doppler shift? a. the speed of sound in tissue increases b. Doppler angle of 75 degrees c. increased transducer frequency d. all of the above
C.
If the relative output power of an ultrasound instrument is calibrated in decibels and the operator increases the output by 20 dB, the beam intensity is increased by: a. 20 times b. 5 % c. 100 times d. one million times
C. 100 times
The echo intensity on a gray scale of 32 shades is represented by the binary number: a. 10101 b. 1010 c. 100000 d. 110000
C. 100000
The best obtainable angle of insonation for vascular evaluation that is most commonly used to provide Doppler shift information is ___ degrees a. 0 b. 45 c. 60 d. 90
C. 60
Refraction often causes a type of artifact known as: a. Mirror image b. grating lobes c. lateral position error d. side lobes
C. Lateral position error
Which imaging technique has the best temporal resolution? a. PW Doppler b. 2D imaging c. M-mode d. Color Doppler
C. M-mode
In a pulsed wave system, how often the blood flow is sampled is determined by the _____ a. Nyguist limit b. SPL c. PRF d. Pulse duration
C. PRF As PRF increases, the pulses are emitted at a faster rate which leads to faster sampling
What is the method used to estimate the ankle blood pressure in a standing patient? a. systolic blood pressure X 2 b. Diastolic blood pressure X 2 c. Add 100mmHg to the systolic blood pressure d. Add 100 mmHg to the diastolic blood pressure
C. add 100 mmHg to the systolic blood pressure
The lateral resolution of an ultrasound system depends on: a. the aperture b. transducer frequency c. A&B d. none of the above
C. both aperture and frequency
With oblique incidence, if the propagation speeds of two media are equal, incidence angle equals a. reflection angle b. transmission angle c. A & B d. none of the above
C. both reflection and transmission
Which of the following correctly describes power Doppler? a. Color is assigned based on the size of red blood cells moving in a direction b. Much mores sensitive to higher flow velocities than color Doppler c. Color display is not angle dependent d. allows evaluation of approximate flow velocity
C. color display is not angle dependent
If the amount of damping decreases, the bandwidth : a. Stays the same b. increases c. decreases d. damping and bandwidth are unrelated
C. decreases
Preprocessing of the information that is fed to the scan converter: a. enlarges each pixel to provide a magnified image b. determines the cathode ray tube brightness assigned to stored grayscale levels c. determines the assignment if echoes to predetermined gray levels d. determines the grayscale emphasis of stored gray levels
C. determines the assignment if echoes to predetermined gray levels
Which of the following is a limitation to Power Doppler? a. inability to display flow velocities greater than 150 cm/s b. only detects flow moving toward the probe c. has slower frame rate than color Doppler d. inability to display flow velocities less than 10 cm/s
C. has slower frame rate than color Doppler
The sonographer may avoid aliasing by altering the: a. transmit gain b. increasing the sample volume length c. image depth d. increasing the frequency
C. image depth increase PRF-increase doppler velocity scale, decrease transmit frequency, increase doppler incident angle, shift the zero baseline, and use CW Doppler
Increasing the # of pulses in a color packet will: a. decrease color sensitivity b. increase frame rate c. increase frame time d. increase color priority
C. increase frame TIME
Which of the following will lead to more color displayed in real time in the abdomen aorta? a. increase sample size b. decrease color threshold c. increase frame rate d. decrease color gain
C. increase frame rate
Which of the following will reduce the amount of color Doppler info displayed on the image? a. increased packet size b. increased sensitivity c. increased sample size d. increased probe frequency
C. increased sample size
Which of the following is NOT a method in which venous flow returns to the heart? a. calf muscle pump b. intrathoracic pressure changes c. left ventricle contraction d. venous valves
C. left ventricle Contraction
Transducer frequency is directly proportional to: a. period b. wavelength c. sound intensity d. SPL
C. sound intensity
Resistance to blood flow is primarily controlled by: a. the volume of blood in the vessel b. the length of the vessel c. the radius of the vessel d. the force of cardiac contraction
C. the radius of the vessel
Acoustic impedance is defined as the product of: a. The mismatch between two interfaces b. A change in velocity at oblique incidence c. The speed of the sound in tissue and density of tissue d. the wavelength and frequency
C. the speed of sound in tissue and density of tissue
If i wanted to evaluate the contrast resolution of a transducer or US system i would buy a: a. Doppler phantom b. AIUM 100 mm phantom c. tissue equivalent phantom d. beam profile phantom
C. tissue equivalent phantom
In the fresnal zone, a. the beam diameter is constant b. the beam diameter diverges c. the beam area increases with distance from the transducer d. the beam area decreases with distance from the transducer
D
Which of the following has the lowest intensity? a. SPTP b. SATP c. SPTA d. SATA
D
How many different shades of gray can the human eye discern at one time? a. 16 b. 32 c. 64 d. 100
D. 100
How many bits per pixel can be displayed with 4 bits of memory? a. 2 b. 4 c. 8 d. 16
D. 16
A wave's initial intensity is 2mW/cm^2. There is an increase of 10 dB. What is the final intensity? a. 4 mW/cm^2 b. 8 ^ c. 12 ^ d. 20 ^
D. 20 mW/cm^2
Which imaging technique has the worst temporal resolution? a. PW Doppler b. 2D imaging c. M-mode d. Color Doppler
D. Color Doppler
Which of the following statements correctly describes Power Doppler? a. offers the highest temporal resolution of all ultrasound imaging techniques b. color is assigned to the Doppler shift based on the velocity of moving red blood cells c. demonstrates mean flow velocities of any RBC in the sample d. color is assigned to the Doppler shift based on the # of RBC
D. Color is assigned to the Doppler shift based on the # of RBC
Which component of the Duplex ultrasound system processes the Doppler shift info to provide the Doppler Waveform? a. demodulator b. quadrature phase detector and fast fourier transformer c. quadrature phase detector d. Fast fourier transformer
D. FTT
What testing device is used to measure acoustic output (intensity) level? a. Tissue phantom b. AIUM test phantom c. Doppler flow phantom d. Hydrophone
D. Hydrophone
Which of the following is defined as only the active time? a. DF b. PRF c. Period d. PD
D. PD
The Piezoelectric effect describes how ____ is converted into ____ by a _____ a. electricity; image; display b. ultrasound; heat; tissue c. incident sound; reflected sound; boundary d. ultrasound; electricity; transducer
D. Ultrasound; electricity; transducer
In order to access low velocity flow, which of the following system adjustments should be made? a. decrease wall filter only b. increase scale setting only c. decrease rejection setting only d. decrease rejection and wall filter setting
D. decrease rejection and wall filter setting low velocities are removed from Doppler tracing with increased rejection and wall filter settings, so to access low velocity you should decrease those settings
All of the following can be related to flash artifact except: a. decreased color scale b. decreased color filter c. increased color priority d. decreased color gain
D. decreased color gain
Which of the following is not a technique that will reduce grating lobes? a. tissue harmonic imaging b. apodization c. subdicing d. edge enhancement
D. edge enhancement
If the real time frame rate is increased and the lines per frame are unchanged, what else must happen? a. imaging depth increases b. transducer frequency increases c. the PRF decreases d. imaging depth decreases
D. imaging depth decreases
You are evaluating an obese patient with a known abdominal aortic aneurysm. While using color Doppler to assess flow within the aortic aneurysm, minimal flow is detected in the anechoic lumen. You decrease the color scale and increase the color gain but there is no improvement. Which of the following adjustments will improve the color display on the exam? a. increase color sample size b. decrease color threshold c. switch from a 4MHz curved array to a 4 MHz linear array d. increase the color threshold
D. increase color threshold
With normal circulation, inspiration: a. decreases the venous return to the heart from the upper body b. should have no effect on venous blood return patterns c. increases the arterial recoil during ventricular systole d. increases venous return to the heart from the upper body
D. increase venous return to the heart from the upper body
Which of the following will increase the acoustic exposure to the patient? a. increased receiver amplification b. increased TGC c. Decreased PRF d. increased output gain
D. increased output gain
Increasing gain generally produces the same effort as _______ a. increasing the attenuation b. increasing the compression c. decreasing the amplitude d. increasing the output power
D. increasing the output power
Damping in a transducer: a. reduces the number of cycles in a pulse and increases the quality factor b. Increases the number of cycles in a pulse and increases penetration c. causes poor axial and lateral resolution d. reduces the duty factor and increases the range of transmitted frequencies
D. reduces the duty factor and increases the range of transmitted frequencies
Increasing the ______ will aid in the ability to properly trace the contour of the Doppler waveform a. Wall filter b. velocity scale c. baseline d. sweep speed
D. sweep speed
Which type of resolution is an accurate representation of moving structures? a. Lateral resolution b. Azimuthal resolution c. Spatial resolution d. temporal resolution
D. temporal resolution
Which of the following is not a true statement about a mechanical transducer? a. It uses a motor to steer the beam b. most mechanical transducers are no longer mechanical c. may be focused with a lens or phased focused d. There are no moving parts
D. there are no moving parts
____ phantoms asses PW, CW, color and power mode
Doppler
The _____ phantom measures the period, PRP, PRF, and pulse duration
Hydrophone or microprobe
If the propagation speed is 1.6 mm/us, the US machine assumes a propagation speed that is too ____ and will display reflectors too ____ to the transducer a. high, close to b. high, far from c. low, close to d. low, far from
Low, close to
Which prefix equals 10 ^-3 a. micro- b. milli- c. centi- d. mega-
Milli-
Which of the following produces a pie shaped image? a. linear sequential array b. phased array c. curved sequential array d. convex transducer
Phased array
If the number of lines per frame is kept constant but the PRF is doubled, what is the effect on the maximum frame rate? a. doubled b. halved c. quadrupled d. unchanged
a. doubled
Before recording an image, you increase the cursor angle from the last sample taken and record the new image. How will this change the detected frequency shift in the new image? a. increase b. decrease c. no change d. no change unless stenosis is present
a. increase
A sound beam encounters an interface at a 90 degree angle. If the speed of sound in the first tissue is 1540 m/s and the speed of sound in the second tissue is 1450 m/s, which of the following numbers most closely approximates the angle of beam transmission? a. <90 degrees b. 90 degrees c. > 90 degrees d. need the impedance to compute angle of transmission
b. 90 degrees
A reynold's number greater than 2000 indicates turbulant flow on ____ evaluation a. PW Doppler b. Color Doppler
b. color doppler
Which of the following persistence levels should be used to optimize Color Doppler imaging of the cardiac structures? a. varies with velocity of the blood flow b. low c. medium d. high
b. low low color persistence should be used with moving structures . high color persistance is preferred for slow flow in vessels
if there is no diastolic flow demonstrated on a Doppler tracing of the arcuate artery of the upper pole of the right kidney, what will the resistive index be? a. unable to calculate b. 0 c. 1.0 d. 0.5
c. 1.0 PSV-EDV/PSV example PSV 50cm/s, EDV 0 cm/s 50-0/50=1/.0
Which of the following artifacts cannot be corrected by increasing the wall filter? a. clutter b. beam width c. aliasing d. cross talk
c. aliasing
if red blood cells are traveling towards a transducer, the frequency emitted by the transducer is ____ the frequency reflected from the red blood cells a. greater than b. equal to c. less than
c. less than
In B-mode imaging, amplitude is located on the ___ axis of imaging a. x b. y c. z d. c
c. z
The correct equation for Snell's Law is:
sin of transmission angle = (c2-c1) x sin of incidence angle
____ ____ Phantom assesses the slice thickness and its effect upon the image accuracy
slice thickness
____ ____ Phantom evaluate gray scale and tissue texture, multi focus and adjustable focus phased array transducers
tissue equivalent