Test Review (Chapters 21 & 22)
Which of the following statements are true of a tissue equivalent phantom? (more than one answer may be correct). A. it has the same propagation speed as that of soft tissue B. it attenuates ultrasound at a rate similar to soft tissue C. embedded in it are solid masses and cystic structures D. it is the device if choice for quality assurance studies
A, B, C, and D
Acoustic artifacts include: (More than one answer may be correct) A. Images of reflectors in an inappropriate position B. Images of reflectors with improper shape C. Images of reflectors with incorrect brightness D. Images that do not correspond to anatomical structures
A,B,C, and D An artifact is an error in imaging. All of the following choices indicate a type of error, and therefore, are artifacts
Which statement regarding axial resolution is incorrect? A. Axial resolution artifact is related to beam diameter B. Higher quality images are associated with smaller numbers C. Axial resolution may be reported in units of meters D. Numerically, axial resolution equals one-half the pulse length E. Too few reflectors appear on the image
A. Axial resolution artifact is related to beam diameter
How does slice thickness artifact commonly express itself? A. Fill in of cystic structures B. Improper brightness of reflectors C. Absence of reflectors D. Strong linear echoes
A. Fill in of cystic structures
What form of resolution is evaluated by measuring the width of reflections arising from small, point targets? A. Lateral resolution B. Axial resolution C. Temporal resolution D. Elevational resolution
A. Lateral resolution
Which of the following determines the spatial resolution of a digital display? A. Pixel density B. Number of lines on the display C. Number of bits per pixel D. Spatial pulse length
A. Pixel density
While using a linear sequential array transducer during a color Doppler exam, the shape of the gray scale image is most often _______, whereas the shape of the color Doppler portion of the image is ______. A. Rectangular, parallelogram B. Rectangular, sector C. Sector, trapezoid D. Square, rectangular
A. Rectangular, parallelogram
What is a comet tail artifact's fundamental mechanism of formation? A. Reflection B. Rarefaction C. Refraction D. Attenuation
A. Reflection
Which process causes mirror image artifact? A. Reflection B. Refraction C. Propagation speed error D. Attenuation
A. Reflection
Six distinct, equally spaced reflections appear on an image at ever increasing depths. What type of artifact is this? A. Reverberation B. Ring down C. Mirror imaging D. Longitudinal resolution
A. Reverberation
All of the following artifacts result in the placement of too many echoes on the image EXCEPT: A. Shadowing B. Reverberation C. Mirror image D. Grating lobes
A. Shadowing
Grating lobes are produced by the same mechanism as which other artifact? A. Side lobes B. Reverberation C. Transaxial lobes D. Acoustic speckle
A. Side lobes
Two small cysts, positioned perpendicular to the main axis of a sound beam, are 2.4 mm apart. What determines whether they appear as two distinct images on the system's display? A. The beam width B. The pulse length C. The PRF D. The TGC
A. The beam width
Which artifact is created by sound moving through a medium with a propagation speed less than soft tissue? A. Vertical misregistration B. Horizontal misregistration C. Lateral resolution D. Ring down
A. Vertical misregistration
PART OF TEST 23 & 24!!!!!!!!! Which of the following devices convert ultrasound energy into heat? A. a calorimeter B. a thermocouple C. a hydrophone D. a Schlieren
A. a calorimeter & B. a thermocouple
Which of the following terms best describes the mechanistic investigation of bioeffects? A. cause-effect B. exposure-response C. cause-response D. exposure-cure
A. cause-effect
What is the cause of acoustic speckle? A. its effects are mild and it tends to slightly degrade images B. it is a rare artifact that does not occur in real-time imaging C. its effects are dramatic D. it is eliminated with apolarization
A. its effects are mild and it tends to slightly degrade images
Some ultrasonic bioeffects studies are performed "in vivo". What is the meaning of the term "in vivo"? A. observable in a living body b. observations based on an experiment C. discernible in a test tube D. estimated in a computer simulation
A. observable in a living body
All of the following may be used to evaluate Doppler systems EXCEPT: A. tissue equivalent phantom B. moving belt phantom C. vibrating string phantom D. Doppler phantom
A. tissue equivalent phantom
What is the highest SPTA intensity of an unfocused ultrasound wave where there have been no observed bioeffects? A. 1 mW/cm^2 B. 100 mW/cm^2 C. 1000 mW/cm^2 D. 1 W/cm^2
B. 100 mW/cm^2
The lateral resolution of four ultrasound systems appear below. Which will produce the finest quality picture? A. 2 cm B. 4 mm C. 6 mm D. 8 hm
B. 4 mm
Where is a mirror image artifact located? A. Sometimes shallower on the image than in the body B. Always deeper on the image than in the body C. Sometimes the same depth on the image as in the body D. Never deeper on the image than in the body
B. Always deeper on the image than in the body
What form of resolution is evaluated by visualizing closely spaced pins that are parallel to the sound beam's main axis? A. Lateral resolution B. Axial resolution C. Temporal resolution D. Elevational resolution
B. Axial resolution
When enhancement occurs, where does it appear on the image? A. In the near field B. Deeper than a weak attenuator C. In the far field D. Shallower than a weak reflector
B. Deeper than a weak attenuator
The analysis of Doppler spectra using ________ is most accurate A. Zero-crossing detectors b. Fast Fourier Transforms C. Time interval histograms D. Chirp-Z transforms
B. Fast Fourier Transforms
Two reflections, one true and one artifact, are displayed on an ultrasound image. In the body, only one anatomic structure is present. The correct reflection and the artifact are found side by side. What is the most likely cause of this artifact? A. Mirror image B. Grating lobe C. Enhancement D. Multipath
B. Grating lobe
With standard diagnostic imaging instrumentation, which has the higher numerical value? A. Axial resolution B. Lateral resolution C. Neither; they have identical values
B. Lateral resolution
Which of the following is related to cavitation bioeffects? A. TIS B. MI C. cavitation index D. pulsatility index
B. MI
Which of the following determines the spatial resolution of a display? A. Number of pixels B. Number of lines on the display C. Number of bits per pixel D. Spatial pulse length
B. Number of lines on the display
Side lobe artifact usually results in all of the following except ___________ A. Hollow structures appearing "filled in" on the image B. Reflectors not appearing on an image C. Reflectors appearing in improper locations on the image D. Reflectors appearing in multiple locations on the image
B. Reflectors not appearing on an image
Which technique of linear array transducer design has virtually virtually eliminated the appearance of grating lobe artifact on modern ultrasound systems? A. Demodulation B. Subdicing C. Deconvolution D. None of the above
B. Subdicing
If a sound pulse travels through a large mass at a speed of 1.2 mm/us, what happens to the position of echoes from reflectors deeper than the mass? A. They are placed in too shallow a location on the image B. They are placed in too deep a location on the image C. They are likely to be placed at the correct depth
B. They are placed in too deep a location on the image
Which of these terms best describes the empirical investigation of bioeffects? A. cause-effect B. exposure-response C. cause-response D. exposure-cure
B. exposure-response
Which of the following is NOT a potential mechanism for production of bioeffects from ultrasound exposure to the body? A. temperature elevation B. fractionation C. cavitation D. vibration
B. fractionation
Which of the following epidemiologic studies is considered most likely to produce meaningful results? A. retrospective and prospective B. prospective and randomized C. retrospective and empirical D. prospective and mechanistic
B. prospective and randomize
Which of the following statements regarding cavitation is true? A. it has never been observed in any biologic media B. stable cavitation relates to oscillating bubbles while transient relates to bursting bubbles C. it is a nonlethal bioeffect produced n animal experiments D. waves with peak pressures less than 100 MPa can never induce cavitation
B. stable cavitation relates to oscillating bubbles while transient relates to bursting bubbles
What is epidemiology the study of? A. large groups B. the prevalence of disease C. acoustic bioeffects on the fetus D. "in vitro" effects
B. the prevalence of disease
An ultrasound pulse has a width of 4 mm, a length of 2 mm , and is produced by a transducer 3,000 times per second. What is the best estimate of the system's axial resolution? A. 4 mm B. 2 mm C. 1 mm D. 1,500 Hz
C. 1 mm
Which sound wave is least likely to create cavitation? A. 5 MHz, 2 MPa B. 2 MHz, 4 MPa C. 6 MHz, 2 MPa D. 2 MHz, 2 MPa
C. 6 MHz, 2 MPa
With which if the following pulses would lateral resolution be worst? A. 10 MHz, 4 mm beam diameter, 4 cycles per pulse B. 4 MHz, 4 mm beam diameter, 2 cycles per pulse C. 7.5 MHz, 8 mm beam diameter, 2 cycles per pulse D. 6 MHz, 2 mm beam diameter, 2 cycles per pulse
C. 7.5 MHz, 8 mm beam diameter, 2 cycles per pulse
Which of these pulses is least likely to produce an axial resolution artifact? A. 10 MHz, 8 mm beam diameter, 6 cycles per pulse B. 4 MHz, 4 mm beam diameter, 2 cycles per pulse C. 9 MHz, 8 mm beam diameter, 2 cycles per pulse D. 6 MHz, 2 mm beam diameter, 2 cycles per pulse
C. 9 MHz, 8 mm beam diameter, 2 cycles per pulse
Spectral analysis of color flow Doppler is most commonly performed by which of the following techniques? A. Zero-crossing detectors B. Fast Fourier Transforms C. Autocorrelation D. Chirp-Z transforms
C. Autocorrelation
Where are shadowing artifacts commonly seen on an acoustic scan? A. Deeper than a structure with a high impedance B. Shallower than a structure with a low propagation speed C. Deeper than a structure with a high attenuation D. Alongside of a structure with a low elastance
C. Deeper than a structure with a high attenuation
Ultrasound systems are designed to automatically _______. A. Display similar structures with equal brightness, regardless of depth B. Position structures at the correct depth, regardless of the medium C. Display all reflections on a line corresponding to the main axis of the sound beam, regardless refraction D. Select the optimal beam width based on the clinical application
C. Display all reflections on a line corresponding to the main axis of the sound beam, regardless refraction
With standard diagnostic imaging instrumentation, which has the higher numerical value? A. Axial resolution B. Lateral resolution C. Elevational resolution
C. Elevational resolution
Unexpectedly low attenuation results in which of the artifacts listed below? A. Refraction B. Attenuation C. Enhancement D. Shadowing
C. Enhancement
What is the meaning of the term "analysis" in the context of spectral analysis of Doppler signals? A. Building a sophisticated signal from components B. Building a simplified signal from components C. Identifying the building blocks or components of a complex signal D. Measuring a complex signal, then modifying its information content
C. Identifying the building blocks or components of a complex signal
Which artifact is not affected by the shape or dimensions of an ultrasound pulse? A. Lateral resolution B. Slice thickness C. Mirror imaging D. Longitudinal resolution
C. Mirror imaging
What standard is best used in a quality assurance program? A. Subjective B. Expert C. Objective D. Legislative
C. Objective
What type of artifact causes a reflection to be placed at an incorrect depth? A. Lateral incertitude B. Shadowing C. Range ambiguity D. Indeterminate relaxation
C. Range ambiguity
Which artifact results in improper side-by-side positioning of reflectors? A. Multipath B. Comet tail C. Refraction D. Reverberation
C. Refraction
At what interval should qualify assurance evaluations be performed? A. Weekly B. Daily C. Routinely D. Periodically
C. Routinely
What artifact results from an ultrasound beam having a finite and measurable three-dimensional profile? A. Acoustic speckle B. Multipath artifact C. Slice thickness artifact D. Grating lobe artifact
C. Slice thickness artifact
What assumption is violated when a refracted sound wave is processed? A. Waves travel directly to and from a reflector B. Sound travels at an average speed of 1.54 mm/us C. Sound travels in a straight line D. The acoustic imaging plane is very thin
C. Sound travels in a straight line
If an ultrasound pulse travels through a large mass in the body at a speed of 1.2 mm/us, what happens to the position of all echoes produced from reflectors shallower than the mass? A. They are placed in too shallow a location on the image B. They are placed in too deep a location on the image C. They are likely to be placed at the correct depth
C. They are likely to be placed at the correct depth
With depth resolution, _________ A. Too many reflectors appear on the image B. Reflectors are placed too deep on the image C. Too few reflectors are on the iamge D. Reflectors appear too shallow on the image
C. Too few reflectors are on the image
Which situation will commonly produce reverberation artifact? A. Two masses that lie perpendicular to the sound beam's main axis B. Two weak reflectors that lie close to each other along the axis if the beam C. Two strong reflectors that lie along the main axis of the beam D. A single highly reflective mass
C. Two strong reflectors that lie along the main axis of the beam
What causes enhancement artifact? A. Sound beams bending B. Linear array transducer architecture C. Unexpectedly low acoustic attenuation D. Acoustic energy radiating in a direction other than the beam's main axis
C. Unexpectedly low acoustic attenuation
Research has indicated that cavitation ________ . A. never occurs B. cannot occur with long pulses C. can be lethal to living things D. effects are purely theoretical
C. can be lethal to living things
Certain studies of bioeffects are performed "in vitro". What is the meaning "in vitro"? A. visible in a living organism B. observations based on experiments C. discernible in a test tube D. perceptible in a living human being
C. discernible in a test tube
Of the following choices, which is considered the most important for the sonographer with regard to bioeffects? A. pulse repetition frequency B. frequency C. duration of the study D. imaging mode
C. duration of the study
Which of the following determines the spatial resolution of an image on a monitor? A. strength of the electron beam B. form of phosphor coating of the screen C. interference of tiny acoustic wavelets D. resonance of particles in the near field
C. interference of tiny acoustic wavelets
Which selection has the highest mechanical index? A. high frequency, high power B. high PRF, high intensity C. low frequency, high pressure D. high spatial pulse length, high PRF
C. low frequency, high pressure
In diagnostic imaging, how does multipath artifact affect the image? A. poor angular resolution B. creation of hyperechoic region C. mild image degradation D. gross horizontal misregistration
C. mild image degradation
The ______ measures beam intensity at specific locations, whereas a _________ measures the entire energy in a sound beam. A. calorimeter, thermocouple B. Schlieren, thermocouple C. thermocouple, calorimeter D. thermometer, hydrometer
C. thermocouple, calorimeter
A comprehensive and scholarly review of bioeffects is performed by the American institute of Ultrasound in Medicine for all of the following reasons EXCEPT: A. ultrasound is a versatile technique B. ultrasound has proven widespread clincial utility C. ultrasound is considered highly toxic D. applications of ultrasound are growing considerably
C. ultrasound is considered highly toxic
Which of the following ultrasound beams has a characteristic that is most likely to cause temperature elevation in soft tissue? A. strongly focused B. medium focused C. unfocused
C. unfocused
The upper limit for the SPTA intensity of a focused ultrasound wave where there have been no observed bioeffects is ________. A. 1 mW/cm^2 B. 10 mW/cm^2 C. 100 mW/cm^2 D. 1 W/cm^2
D. 1 W/cm^2
According to the AIUM, at what "in situ" tissue temperature is there danger to a fetus? A. 100 degrees C B. 98.6 degrees F C. 1 degree F over normal temperature D. 41 degrees C
D. 41 degrees C
What causes side lobe artifact? A. Sound beams bending B. Linear array transducer architecture C. Unexpectedly low acoustic attenuation D. Acoustic energy radiating in a direction other than the beam's main axis
D. Acoustic energy radiating in a direction other than the beam's main axis
When creating an ultrasound image, all of the following assumptions are made EXCEPT: A. Sound travels in a straight line B. Sound travels at 1.54 km/s C. The sound beam is extremely thin D. All structures create reflections of equal magnitude
D. All structures create reflections of equal magnitude
Which of these produces shadowing? A. Reverberation B. Multipath C. Reflection D. Attenuation
D. Attenuation
All of the following are characteristics of a tissue equivalent phantom EXCEPT: A. Speed of sound similar to that in soft tissue B. Attenuation properties similar to that of soft tissue C. Scattering characteristics similar to that of soft tissue D. Density similar to that of soft tissue
D. Density similar to that of soft tissue
Acoustic focusing of an ultrasound beam may create which artifact? A. Side lobes B. Refraction C. Speckle D. Enhancement
D. Enhancement
Which one of these artifacts does not result from multiple reflections? A. Comet tail B. Reverberations C. Ring down D. Enhancement
D. Enhancement
Which of the following statements is true about lateral resolution? A. It is called angular, transverse, and depth resolution B. It is reported in units of time C. It is the same at all depths D. It can be improved by focusing
D. It can be improved by focusing
Which artifact is not related to the unexpected reflection of an acoustic wave? A. Multipath B. Comet tail C. Reverberation D. Lateral resolution
D. Lateral resolution
Grating lobes are most common with which type of transducer technology? A. Annular array B. Continuous wave C. Mechanical scanners D. Linear arrays
D. Linear arrays
Two distinct reflections are observed on an image, but they actually arise from a single anatomic structure. The artifact is positioned deeper than the correct reflection. What is the most likely cause of this artifact? A. Grating lobe B. Side lobe C. Refraction D. Mirror image
D. Mirror image
Axial resolution artifacts are due to which of the following? A. Multiple reflections B. Beam width C. Attenuation D. Pulse length
D. Pulse length
What is the most likely cause of ring down artifact? A. Refraction B. Inversion C. Reabsorption D. Reflection
D. Reflection
How is shadowing artifact expressed? A. Positioning structures too deep on the image B. Locating structures in improper lateral position C. Placing reflections in multiple locations D. Reflectors being absent on the image
D. Reflectors being absent on the image
Which artifact is unrelated to the dimensions of an ultrasound pulse? A. Lateral resolution B. Depth resolution C. Slice thickness D. Refraction
D. Refraction
Which artifact produces an image with an incorrect number of reflectors? A. Propagation speed error B. Multipath C. Enhancement D. Side lobes
D. Side lobes
While imaging a test object, an ultrasound system displays one image 1.8 cm deeper than another. Upon measuring the test object, it is found that it is actually 2.0 cm deeper. What conclusion can be drawn from this? A. Speed of sound in the test object is the same as soft tissue B. Speed in the test object is less than that in soft tissue C. Attenuation of sound in the test object is less than that in soft tissue D. Speed in soft tissue is less than that of the test object
D. Speed in soft tissue is less than that of the test object
What are the characteristics of a medium that produces comet tail artifact? A. Weak reflectors, closely spaced, low propagation speeds B. Strong reflectors, widely spaced, high propagation speeds C. Strong reflectors, closely spaced, low propagation speed D. Strong reflectors, closely spaced, high propagation speed
D. Strong reflectors, closely spaced, high propagation speed
When studying bioeffects, which research approach is more important? A. empirical B. mechanistic C. neither is important D. both are equally important
D. both are equally important
Epidemiologic studies of "in utero" exposure to ultrasound have included all of the following findings EXCEPT _______. A. birth weight B. cancer C. structural abnormalities D. none of the above
D. none of the above
Which component of an ultrasound system exposes a patient to greatest risk? A. the CRT B. the electric cord C. the pulser D. the transducer
D. the transducer
Under which condition is it permissible to perform a diagnostic ultrasound exam? A. when the patient will benefit B. when the patient has insurance C. when the exam is perfectly safe D. when the benefits outweigh the risks
D. when the benefits outweigh the risks
Which of the following is not a potential cause of artifact in diagnostic imaging? A. Operator error B. Equipment malfunction C. Patient motion D. Ultrasound physics E. None of the above
E. None of the above
Which modes of Doppler may be assessed with a Doppler phantom? A. color flow Doppler B. pulsed Doppler C. power mode Doppler D. continuous wave Doppler E. all of the above
E. all of the above
True or false? A bioeffect identified through the mechanistic approach rather than the empirical approach is more likely to have clinical significance.
False
True or false? All artifacts are errors in imaging that do not represent the true anatomy of the imaged organ. Therefore, they are all undesirable and should be eliminated if possible
False
True or false? It is generally believed that the effects of ultrasound on biologic media are minimal.
False
True or false? Quality assurance evaluations of ultrasound systems can only be performed by biomedical engineers or physical scientists.
False
True or false? Quality assurance evaluations of ultrasound systems should be performed weekly.
False
True or false? The AIUM suggests that "in vitro" research confirming bioeffects is valuable and valid. Their results are significant and should be directly applied to the clinical arena.
False
True or false? The biological effects of ultrasound are thought to be negligible and thus, few investigations have been performed on the subject.
False
True or false. It is common to visualize artifacts when the dimension of the sound beam is larger than the reflector's dimension.
True
True or false. Mirror image artifacts always appear deeper than the true anatomy.
True
True or false? Artifacts are likely to appear when the dimensions of the sound beam are are larger than the dimensions of the reflectors in the body
True
True or false? Focused sound beams are considered less likely to create bioeffects because the beams will strike fewer gas bubbles that could potentially cavitate.
True
True or false? Grating lobes are a result of substantial acoustic energy directed outward from a linear array transducer, but not along the main axis of the sound beam.
True
True or false? Grating lobes are attributed only to array transducers.
True
True or false? It is generally believed that the ultrasound bioeffects are minimal at intensity levels typical of those produced by diagnostic imaging equipment.
True
True or false? One reason focused ultrasound beams with low intensities are less likely to cause bioeffects is that a focused beam is less efficient in hating a large mass of tissue to a critical temperature.
True
True or false? Proper quality assurance programs require the assessment of every transducer used in the clinical laboratory.
True
True or false? Side lobe, grating lobe, and refraction artifacts all reduce lateral resolution
True
True or false? The empirical approach to the study of bioeffects and ultrasonic safety surveys data involves finding a relationship between exposure and toxic effects.
True
True or false? The mechanistic approach to the study of bioeffects and safety includes the identification of a theoretical construct that could produce an effect.
True
True or false? the AIUM considers an ultrasound-induced biologic tissue temperature rise of less than 2 degrees Centigrade above normal body temperature as safe for clinical studies.
True