ARDMS SPI Dumps Questions Answers

Comprehensive and Detailed Explanation From Exact Extract:

Persistence averages multiple frames to smooth out random noise fluctuations, reducing the appearance of noise in the image and improving image quality.

According to sonography instrumentation reference:

“Persistence reduces noise by averaging data from consecutive frames, improving signal-to-noise ratio and producing a smoother image.”

Therefore, the correct answer is D: Increase persistence.

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Comprehensive and Detailed Explanation From Exact Extract:

When color "bleeds" outside vessel walls, it often results from motion artifacts or noise from slow tissue motion being displayed as flow. Increasing the wall filter eliminates low-frequency Doppler shifts caused by motion, improving color accuracy within vessel boundaries.

According to sonography instrumentation reference:

“Raising the wall filter eliminates low-velocity signals from vessel wall motion, reducing the appearance of color outside the vessel lumen.”

Therefore, the correct answer is C: Increasing wall filter.

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Aliasing in pulsed-wave Doppler occurs when the sampled Doppler frequency exceeds the Nyquist limit, which is half of the pulse repetition frequency (PRF). This results in an incorrect representation of the blood flow velocities, causing the waveform to wrap around and appear on the opposite side of the baseline. To correct aliasing, the PRF should be increased, which raises the Nyquist limit and allows for accurate measurement of higher velocities without aliasing. Increasing the PRF effectively reduces the likelihood of aliasing artifacts in the Doppler signal.

American Registry for Diagnostic Medical Sonography (ARDMS). Sonography Principles and Instrumentation (SPI) Examination Review Guide.