Chapter 6 Flashcards
There must be \_\_\_\_\_\_ samples per cycle of Doppler shift to correctly obtain an image. A. Two B. Three C. Four D. Five
A. Two
Which of the following is not a form of reverberation artifact? A. Comet tail B. Ring down C. Mirror image D. Speckle
D. Speckle
Which artifact displaces structures axially? A. Speed error B. Grating lobes C. Refraction D. Reverberation
A. Speed error
Mirror-image artifact is a form of \_\_\_\_\_. A. Refraction B. Reverberation C. Speed error D. Grating lobes
B. Reverberation
Weakening of echoes distal to a strongly attenuating structure describes \_\_\_\_\_\_. a. Comet tail B. Enhancement C. Shadowing D. Ring down
C. Shadowing
Which of the following would most likely and eliminate spectral aliasing?
A. Increasing the Doppler angle
B. Increasing the transducer frequency
C. Decreasing the pulse repetition frequency
D. Increasing the depth of the sample volume
A. Increasing the Doppler angle
Section thickness artifact is also called \_\_\_\_\_\_. A. Partial volume artifact B. Ring down artifact C. Comet tail artifact D. Resonance phenomenon
A. Partial volume artifact
Which type of artifact is most likely to produce a doubling of a single image? A. Reflection B. Refraction C. Reverberation D. Section thickness
B. Refraction
Axial resolution is determined by \_\_\_\_\_\_ and lateral resolution is determined by \_\_\_\_\_\_. A. Pulse width; pulse length B. Pulse length; pulse width C. Pulse width; operating frequency D. Operating frequency; pulse length
B. Pulse length; pulse width
Speckle artifact is messed likely caused by \_\_\_\_\_\_. A. Refraction B. Interference C. Pulse width D. Multiple reflections
B. Interference
Mirror image is commonly seen around which structure? A. Kidney B. Stomach C. Pancreas D. Diaphragm
D. Diaphragm
Enhancement of an echo results from a structure having \_\_\_\_\_\_ than surrounding structures. A. Higher impedance B. Lower density C. Higher attenuation D. Lower attenuation
D. Lower attenuation
Multiple reflections between two structures describes A. Refraction B. Mirror image C. Reverberation D. Speed error
C. Reverberation
How is detail resolution artifactual?
A. There is a failure to resolve two reflectors.
B. Actual size of structure is decreased.
C. To adjacent structures are resolved.
D. Multiple reflections are displayed beneath the real reflector.
A. There is a failure to resolve two reflectors
The comet tail artifact is a case of\_\_\_\_\_\_. A. Refraction B. Resolution C. Attenuation D. Reverberation
D. Reverberation
Which of the following is an effect of refraction?
A. Shadowing at the edge of structures.
B. Two adjacent structures seen as one.
C. Incorrect representation of tissue density.
D. Structures displayed medial from correct location
A. Shadowing at the edge of structures
Received echoes originating off center from the central beam are caused by \_\_\_\_\_. A. Speckle B. Speed error C. Range ambiguity D. Section thickness
D. Section thickness
Which of the following artifacts is exclusive to pulse-Doppler imaging? A. Aliasing B. Mirror image C. Enhancement D. Rand ambiguity
A. Aliasing
Which of the following artifacts may display in incorrect shape of a structure? A. Mirror image B. Reverberation C. Grating lobes D. Propagation speed error
d. Propagation speed error
Which of the following artifacts would most likely place an echo at a depth much closer to the surface than it originated? A. Speed error B. Mirror image C. Slice thickness D. Range ambiguity
D. Range ambiguity