What is required when interrogating higher blood velocities at angles closer to zero degrees?

Comprehensive and Detailed Explanation From Exact Extract:

When evaluating high blood velocities, especially at angles closer to zero degrees (which produces maximum Doppler shifts), aliasing can easily occur because the Doppler frequency shift increases. To avoid aliasing, you must increase the Doppler scale (which increases the pulse repetition frequency, PRF) to accommodate these higher velocities.

According to sonography instrumentation references:

“The Doppler scale (PRF) must be increased when high velocities are anticipated to prevent aliasing, especially at optimal Doppler angles near zero degrees where maximum frequency shifts occur.”

Therefore, the correct answer is C: Increased Doppler scale settings.

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