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.

Accepted Answer

Mirror-image artifact occurs when an ultrasound beam is reflected off a strong reflector, such as the diaphragm, and then encounters another structure, like the liver, creating a mirror image of the structure above the diaphragm.

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

Accepted Answer

Shifting the baseline can help eliminate aliasing by adjusting the display of the Doppler spectrum, effectively "cutting and pasting" the waveform to fit within the display range.

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.

Accepted Answer

The Nyquist limit is the maximum frequency that can be accurately sampled by a pulsed Doppler system to avoid aliasing, which is the misinterpretation of high frequencies as lower ones.

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.

Accepted Answer

Aliasing occurs in Doppler studies when the sampling rate is too low to accurately measure high velocities, leading to an incorrect representation of the direction or velocity of flow.

Question 5

Artifacts caused by sonographic technique include all of the following except:
A) noise.
B) banding.
C) side lobes.
D) breathing.

Accepted Answer

The answer of Artifacts caused by sonographic technique include all...

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.

Accepted Answer

Shadowing is the reduction in echo amplitude from reflectors that lie behind a strongly reflecting or attenuating structure. This occurs because the strong reflector or attenuator reduces the ultrasound beam intensity, making it difficult for the ultrasound to detect echoes from structures located behind it.

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.

Accepted Answer

Lack of axial and lateral resolution leads to failure in distinguishing between closely spaced structures, resulting in loss of detail in the ultrasound image.

Question 8

Refraction can cause a reflector that is:
A) missing.
B) not real.
C) misplaced.
D) of improper brightness.

Accepted Answer

Refraction can cause a reflector to appear misplaced due to the bending of light as it passes through different mediums, which can change the apparent position of the reflector.

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

Accepted Answer

Grating lobes are a form of ultrasound artifact that occur when the beam width is not uniform across the scan plane. Echoes from grating lobes can be imaged if they fall within an anechoic region, which is a region that does not produce echoes under normal circumstances, making any artifactually generated echoes more noticeable.

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

Accepted Answer

Bone is highly reflective of ultrasound waves, leading to strong posterior shadowing as the ultrasound waves are significantly attenuated or blocked after hitting the bone, preventing them from penetrating further.

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.

Accepted Answer

Mirror image artifacts occur when the ultrasound beam reflects off a strong reflector (like the diaphragm) and then off another structure, before returning to the transducer. This causes the machine to incorrectly place the echo in a location that makes it appear as if there is a symmetrical structure on the other side of the strong reflector.

Question 12

Identify the artifact commonly seen with pulsed wave Doppler imaging.
A) Noise
B) Aliasing
C) Mirror image
D) Range ambiguity

Accepted Answer

Aliasing is a common artifact seen with pulsed wave Doppler imaging, occurring when the Doppler shift exceeds half the pulse repetition frequency, leading to incorrect velocity representation.

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.

Accepted Answer

The phenomenon described is known as "enhancement." It occurs when echoes from structures behind a weakly attenuating (or less dense) area appear brighter on an ultrasound image. This is because the ultrasound waves are not significantly weakened by the preceding structure, leading to stronger echoes from the structures behind it.

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

Accepted Answer

Decreasing the transducer frequency lowers the Doppler shift frequency, which can help reduce or eliminate aliasing.

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

Accepted Answer

Speckle is a granular texture that commonly appears in medical ultrasound images as a result of constructive and destructive interference of the returning echoes from the scatterers within the tissue. This interference pattern creates the speckle artifact, which can affect the image quality but also provides tissue-specific information.

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.

Accepted Answer

Reverberation occurs when an ultrasound wave is trapped between two strong reflectors, such as the transducer and a strong reflector, causing multiple reflections that are displayed as equally spaced echoes on the ultrasound image.

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

Accepted Answer

Shifting the baseline and increasing the pulse repetition frequency are common and convenient solutions to aliasing in Doppler ultrasound. Shifting the baseline allows for a better representation of blood flow velocities that exceed the Nyquist limit, while increasing the pulse repetition frequency (PRF) directly addresses the root cause of aliasing by allowing the system to sample the velocity of blood flow more frequently, thus reducing the likelihood of velocities appearing to wrap around from positive to negative or vice versa.

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.

Accepted Answer

Decreasing the Doppler gain specifically reduces the amplification of the received Doppler signal, which includes both the desired signal from blood flow and any internally generated electronic noise. By lowering the Doppler gain, the sonographer can decrease the level of this noise, improving the quality of the Doppler signal without affecting the overall imaging settings.

Question 19

Increased intensity in the focal region of the sound beam is called focal ___________________.
A) zones
B) intensity
C) banding
D) attenuation

Accepted Answer

Focal banding refers to the increased intensity in the focal region of a sound beam, often due to the focusing characteristics of the ultrasound transducer.

Question 20

Shadowing is reduced by using:
A) harmonics imaging.
B) pixel interpolation.
C) three-dimensional imaging.
D) spatial compounding.

Accepted Answer

Spatial compounding reduces shadowing by using multiple angles of insonation to fill in shadowed areas, improving image quality.

Quiz 7: Imaging and Doppler Artifacts

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

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

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

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

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

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

Lack of axial and lateral resolution result in:

Refraction can cause a reflector that is:

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

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

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:

Identify the artifact commonly seen with pulsed wave Doppler imaging.

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

Which one of the following will reduce or eliminate aliasing?

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

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

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

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

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

Shadowing is reduced by using: