Deck 7: Imaging and Doppler Artifacts

Question 1

The best example of a mirror-image artifact is seen with the:

A) gallbladder and cystic duct.
B) pancreas and duodenum.
C) uterus and fallopian tube.
D) diaphragm and liver.

Answer 1

D

Question 2

Which one of the following eliminates aliasing using the "cut and paste" technique?

A) Shifting the baseline
B) Decreasing the Doppler angle
C) Increasing the transducer frequency
D) Increasing the pulse repetition frequency

Answer 2

A

Question 3

The upper limit to the pulsed wave Doppler shift that can be properly detected by pulsed instruments is called:

A) aliasing.
B) Nyquist limit.
C) shadowing.
D) speed error.

Answer 3

B

Question 4

Insufficient sampling during a Doppler study that results in the improper representation of information is known as:

A) multiple reflection.
B) resonance.
C) aliasing.
D) enhancement.

Question 5

Artifacts caused by sonographic technique include all of the following except:

A) noise.
B) banding.
C) side lobes.
D) breathing.

Question 6

The reduction in echo amplitude from reflectors that lie behind a strongly reflecting or attenuating structure is:

A) enhancement.
B) resonance.
C) comet tail.
D) shadowing.

Question 7

Lack of axial and lateral resolution result in:

A) echoes originating only from the center of the beam.
B) decrease in ultrasound pulse length and width in the scan plane.
C) Failure to resolve structures and detail loss.
D) beam width artifacts on the scan plane.

Question 8

Refraction can cause a reflector that is:

A) missing.
B) not real.
C) misplaced.
D) of improper brightness.

Question 9

Echoes resulting from grating lobes may be imaged if they fall within a(n) ___________ region.

A) complex
B) anechoic
C) echogenic
D) hypoechoic

Question 10

Which one of the following structures is most likely to demonstrate strong posterior shadowing?

A) Cyst
B) Air
C) Bone
D) Blood vessel

Question 11

The artifact that shows structures that exist on one side of a strong reflector as being present on the other side as well is known as:

A) range ambiguity.
B) mirror image.
C) refraction.
D) speed error.

Question 12

Identify the artifact commonly seen with pulsed wave Doppler imaging.

A) Noise
B) Aliasing
C) Mirror image
D) Range ambiguity

Question 13

The strengthening of echoes from reflectors that lie behind a weak attenuating structure is:

A) aliasing.
B) multiple reflection.
C) resonance.
D) enhancement.

Question 14

Which one of the following will reduce or eliminate aliasing?

A) Decreasing the Doppler angle
B) Decreasing the transducer frequency
C) Increasing the depth of the sample volume
D) Decreasing the pulse repetition frequency

Question 15

Which one of the following artifacts results from constructive and destructive interference of the returning echoes?

A) Noise
B) Speckle
C) Speed error
D) Range ambiguity

Question 16

Multiple reflections can occur between the transducer and a strong reflector. This is an example of:

A) reverberation.
B) mirror image.
C) speckle tracking.
D) refraction.

Question 17

Which of the following solutions are common and convenient to aliasing?

A) Shifting the baseline and decreasing the pulse repetition frequency
B) Decreasing the pulse repetition frequency and increasing the depth of the sample gate
C) Shifting the baseline and increasing the pulse repetition frequency
D) Increasing the pulse repetition frequency and increasing the depth of the sample gate

Question 18

To decrease internally generated electronic noise in the Doppler signal, the sonographer should decrease the:

A) Doppler gain.
B) overall gain.
C) imaging depth.
D) transducer frequency.

Question 19

Increased intensity in the focal region of the sound beam is called focal ___________________.

A) zones
B) intensity
C) banding
D) attenuation

Question 20

Shadowing is reduced by using:

A) harmonics imaging.
B) pixel interpolation.
C) three-dimensional imaging.
D) spatial compounding.

Question 21

Increasing the pulse repetition frequency increases the chances of displaying which one of the following artifacts?

A) Speckle
B) Aliasing
C) Mirror image
D) Range ambiguity

Question 22

Cross-talk can produce which one of the following artifacts?

A) Noise
B) Aliasing
C) Mirror image
D) Range ambiguity

Question 23

Refraction of the sound beam at a boundary may result in false sonographic ________________.

A) brightness
B) duplication
C) shadowing
D) enhancement

Question 24

Reverberation artifact displays structures that are:

A) not real.
B) misplaced.
C) improper in shape.
D) improper in brightness.

Question 25

The width of the pulse determines ______________ resolution.

A) temporal
B) lateral
C) axial
D) contrast