Free ARDMS SPI Exam Dumps

Comprehensive and Detailed Explanation From Exact Extract:

The end-diastolic velocity represents the lower velocity portion of the Doppler waveform. The wall filter (or high-pass filter) removes low-frequency Doppler shifts from the spectral display. When the wall filter is increased, it filters out these low-velocity signals --- including diastolic flow components. According to sonography Principles and Instrumentation reference materials:

'The wall filter eliminates low-velocity signals from the Doppler spectrum. Increasing the wall filter may completely eliminate end-diastolic velocities, especially in low-resistance arterial flow.'

Therefore, the correct answer is D: Increased wall filter.

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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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Range ambiguity artifact occurs when echoes from one pulse are received after the next pulse has been emitted, leading to the incorrect placement of echoes at shallower depths than their true location. This artifact typically happens when the PRF is set too high, causing the ultrasound system to interpret delayed echoes as coming from the current pulse rather than the previous one. This results in reflectors appearing closer to the transducer than they actually are.

ARDMS Sonography Principles & Instrumentation Guidelines

Kremkau FW. Sonography Principles and Instruments. 9th ed. Philadelphia, PA: Elsevier; 2016.