SPI Exam Dumps : Sonography Principles and Instrumentation

Comprehensive and Detailed Explanation From Exact Extract:

Using multiple focal zones improves lateral resolution but requires additional time for each focal zone acquisition, which reduces frame rate and therefore degrades temporal resolution.

According to sonography instrumentation reference:

“Multiple focal zones improve lateral resolution but at the expense of temporal resolution due to longer acquisition time for each frame.”

Therefore, the correct answer is D: Temporal.

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Which setting is the most likely cause of the artifact displayed in this image?

A close-up of a ultrasound Description automatically generated

A. Color gain set too low

B. Color gain set too high

C. Velocity scale set too high

D. Velocity scale set too low

Answer: D

Comprehensive and Detailed Explanation From Exact Extract:

The image shows color aliasing, where the colors abruptly change within the vessel indicating wrap-around of Doppler shifts. This happens when the velocity scale (PRF) is set too low, causing velocities exceeding the Nyquist limit to alias.

According to sonography instrumentation reference:

“Aliasing occurs in color Doppler when the flow velocities exceed the Nyquist limit, commonly due to a low velocity scale (PRF).”

Therefore, the correct answer is D: Velocity scale set too low.

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When the depth of imaging is increased, the time it takes for the ultrasound pulses to travel to and from the deeper structures also increases, which can reduce the frame rate. To maintain the same frame rate, one effective adjustment is to decrease the image width. Narrowing the image width reduces the number of scan lines required to create each frame, allowing the system to maintain a higher frame rate despite the increased depth.

ARDMS Sonography Principles and Instrumentation guidelines

Kremkau, F. W. (2015). Diagnostic Ultrasound: Principles and Instruments.

Color flash artifact occurs due to tissue motion. This artifact is a type of color Doppler artifact that happens when there is movement of tissue or transducer, which causes the Doppler system to incorrectly interpret the motion as blood flow. This results in a flash of color appearing on the image where there is actually no flow. Tissue motion affects the Doppler signal, leading to misinterpretation by the system, and hence the artifact appears as a flash of color.

References

ARDMS Sonography Principles and Instrumentation (SPI) Exam Study Guide

"Diagnostic Ultrasound: Principles and Instruments" by Frederick W. Kremkau