# Chapter 6 Flashcards Preview

## Second Half of Physics Exam > Chapter 6 > Flashcards

Flashcards in Chapter 6 Deck (50)
1
Q
```There must be \_\_\_\_\_\_ samples per cycle of Doppler shift to correctly obtain an image.
A. Two
B. Three
C. Four
D. Five```
A

A. Two

2
Q
```Which of the following is not a form of reverberation artifact?
A. Comet tail
B. Ring down
C. Mirror image
D. Speckle```
A

D. Speckle

3
Q
```Which artifact displaces structures axially?
A. Speed error
B. Grating lobes
C. Refraction
D. Reverberation```
A

A. Speed error

4
Q
```Mirror-image artifact is a form of \_\_\_\_\_.
A. Refraction
B. Reverberation
C. Speed error
D. Grating lobes```
A

B. Reverberation

5
Q
```Weakening of echoes distal to a strongly attenuating structure describes \_\_\_\_\_\_.
a. Comet tail
B. Enhancement
D. Ring down```
A

6
Q

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

A. Increasing the Doppler angle

7
Q
```Section thickness artifact is also called \_\_\_\_\_\_.
A. Partial volume artifact
B. Ring down artifact
C. Comet tail artifact
D. Resonance phenomenon```
A

A. Partial volume artifact

8
Q
```Which type of artifact is most likely to produce a doubling of a single image?
A. Reflection
B. Refraction
C. Reverberation
D. Section thickness```
A

B. Refraction

9
Q
```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```
A

B. Pulse length; pulse width

10
Q
```Speckle artifact is messed likely caused by \_\_\_\_\_\_.
A. Refraction
B. Interference
C. Pulse width
D. Multiple reflections```
A

B. Interference

11
Q
```Mirror image is commonly seen around which structure?
A. Kidney
B. Stomach
C. Pancreas
D. Diaphragm```
A

D. Diaphragm

12
Q
```Enhancement of an echo results from a structure  having \_\_\_\_\_\_ than surrounding  structures.
A. Higher impedance
B. Lower density
C. Higher attenuation
D. Lower attenuation```
A

D. Lower attenuation

13
Q
```Multiple reflections between two structures describes
A. Refraction
B. Mirror image
C. Reverberation
D. Speed error```
A

C. Reverberation

14
Q

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

A. There is a failure to resolve two reflectors

15
Q
```The comet tail artifact is a case of\_\_\_\_\_\_.
A. Refraction
B. Resolution
C. Attenuation
D. Reverberation```
A

D. Reverberation

16
Q

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

A. Shadowing at the edge of structures

17
Q
```Received echoes originating off center from the central beam are caused by \_\_\_\_\_.
A. Speckle
B. Speed error
C. Range ambiguity
D.  Section thickness```
A

D. Section thickness

18
Q
```Which of the following artifacts is exclusive to pulse-Doppler imaging?
A. Aliasing
B. Mirror image
C. Enhancement
D. Rand ambiguity```
A

A. Aliasing

19
Q
```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```
A

d. Propagation speed error

20
Q
```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```
A

D. Range ambiguity

21
Q
```Which of the following would likely demonstrate acoustic enhancement?
A. Liver
B. Pancreas
D. Falciform ligament```
A

22
Q

The Nyquist limit is ______.
A. Oversampling of the Doppler shifts
B. Even and odd multiples of the frequency
C. The upper limit to the Doppler shift that can be properly detected
D. The number at which turbulence is detected

A

C. The upper limit to the Doppler shift that can be properly detected

23
Q
```Which of the following almost likely cause range ambiguity?
A. High wall filter setting
B. High operating frequency
C. Multiple sample volumes
D. High pulse repetition frequency```
A

D. High pulse repetition frequency

24
Q

The Nyquist limit describes the ______.
A. Flow speed through a stenosis
B. Driving force behind blood flow
C. Resistance of blood flow in a straight tube
D. Minimum number of samples required to avoid aliasing

A

D. Minimum number of samples required to avoid a aliasing.

25
Q
```If the pulse repetition frequency (PRF) is 6 kHz, which of the following Doppler shifts will cause aliasing?
A. 1 kHz
B. 2 kHz
C. 3 kHz
D. 4kHz```
A

D. 4kHz

26
Q
```Which of the following types of artifacts can be beneficial?
A. Refraction
B. Attenuation
C. Propagation
D. Reverberation```
A

B. Attenuation

27
Q

When imaging deep structures, which of the following automatically occurs?
A. Frame rate increases.
B. Nyquist limit increases.
C. Pulse repetition (PRP) is reduced.
D. Pulse repetition frequency (PRF) is reduced.

A

D. Pulse repetition frequency (PRF) is reduced.

28
Q
```Under-sampling the Doppler shift is likely to cause \_\_\_\_\_\_.
A. Aliasing
C. A mirror image
D. Range ambiguity```
A

A. Aliasing

29
Q
```Which of the following results from the underlying distribution of scatterers?
A. Speckle
B. Ring-down
C. Comet tail
D. Section thickness```
A

A. Speckle

30
Q

Which of the following is a result of sound refraction?
A. Axial duplication of structures.
B. Displacement of structures axially.
C. Displacement of structures laterally.
D. Multiple equally spaced linear reflections.

A

C. Displacement of structures laterally.

31
Q
```Reflected echoes displaying falsely high amplitudes describe \_\_\_\_\_\_.
A. Speckle
C. Enhancement
D. Speed error```
A

C. Enhancement

32
Q
```Color Doppler mirror image artifact is commonly displayed when imaging which of the following vessels?
A. Abdominal aorta
B. Subclavian artery
C.  Internal jugular vein
D. Common carotid artery```
A

B. Subclavian artery

33
Q
```A reduction in echo amplitude from reflectors behind a strongly reflecting structure is called \_\_\_\_\_.
A. Speckle
B. Comet tail
D. Enhancement```
A

34
Q
```Equally spaced reflections that decrease in amplitude with increases in depth describe \_\_\_\_\_\_\_.
A. Refraction
B. Attenuation
C. Reverberation
D. Axial resolution```
A

C. Reverberation

35
Q
```Which of the following artifacts appears as a series of closely spaced discrete echoes distal to a strongly reflective structure?
A. Ring down
B.  Comet tail
C. Refraction
D. Grating lobes```
A

B. Comet tail

36
Q
```Which of the following would least likely cause acoustic shadowing?
A.  Gallstone
B.  Bowel gas
D. Uterine fibroid```
A

37
Q
```Which of the following is a common and convenient solution to eliminate aliasing?
A. Increasing the transducer frequency
B. Decreasing pulse repetition frequency
C. Decreasing transducer frequency
D.  Shifting the baseline```
A

D. Shifting the baseline

38
Q

Which of the following can be considered a “cut-and-paste” technique of eliminating aliasing?
A. Shifting the baseline
B. Increasing the pulse repetition frequency
C. Decreasing the depth of the sample volume
D. Increasing the Doppler angle

A

A. Shifting the baseline

39
Q
```Multiple sample gates will appear \_\_\_\_\_\_\_.
A. To manage range ambiguity
B. When utilizing power Doppler
C. When multiple focal zones are used
D. With a low pulse repetition frequency```
A

A. To manage range ambiguity

40
Q
```If the propagation speed that exists over a path traveled is 1.44 mm/us, the display will place the echo \_\_\_\_\_\_.
A. Too far from the transducer
B.  Lateral from the actual location
C.  Too close to the transducer
D.  Medial from the actual location```
A

A. Too far from the transducer

41
Q
```Increasing the pulse repetition frequency to avoid  aliasing can cause \_\_\_\_\_\_.
A. Clutter
B. Speckle
C. Mirror image
D. Range ambiguity```
A

D. Range ambiguity

42
Q

The assumptions in the design of sonographic instruments include all of the following except _______.
A. Sound travels in a straight line
B. Sound travels at different speeds in soft tissue
C. Echoes originate from objects located on the beam axis
D. Echogenicity is a property of the structure

A

B. Sound travels at different speeds in soft tissue

43
Q
```Edge shadowing is a result of \_\_\_\_\_\_.
A. Refraction of the sound beam
B. Attenuation of the sound beam
C. Reflection of the sound beam
D. Reverberation of the sound beam```
A

A. Refraction of the sound beam

44
Q
```Propagation speed error display structures \_\_\_\_\_\_\_.
A. Axially
B. Medially
C. Laterally
D. Anteriorly```
A

A. Axially

45
Q

The propagation group of sonographic artifacts includes ______.
A. Comet tail, mirror image, shadowing
C. Grating lobe, enhancement, range ambiguity
D. Mirror image, range ambiguity, slice thickness

A

D. Mirror image, range ambiguity, slice thickness

46
Q
```If the propagation speed through a medium is faster than 1.54 mm/us the reflector will be placed \_\_\_\_\_\_.
A. Medial to the correct position
B. Lateral to the correct position
C. Deeper than the correct position
D. Shallower than the correct position```
A

D. Shallower than the correct position

47
Q
```Range ambiguity produces which error in anatomic imaging?
A. Range too low
B. Range too short
C. Doppler shift too low
D. Doppler shift too high```
A

B. Range too short

48
Q

Section thickness artifact is a result of_______.
A. Interference
B. Pulse length
C. Finite speed of sound in soft tissue
D. Beam width perpendicular to scan plane

A

D. Beam width perpendicular to scan plane

49
Q
```Edge shadowing is caused by
A. Refraction
B. Reverberation
C. Propagation speed error
D. A highly attenuating structure```
A

A. Refraction

50
Q
```Shadowing and enhancement are descriptions of \_\_\_\_\_\_\_ artifacts.
A. Propagation
B. Refraction
C. Attenuation
D. Reverberation```
A

C. Attenuation