SPI Exam Dumps : Sonography Principles and Instrumentation

The purpose of using a spectral Doppler wall filter is to eliminate lower velocity signals. Wall filters are designed to remove low-frequency Doppler shifts caused by the motion of the vessel walls or surrounding tissues, which are generally of no diagnostic value. By eliminating these lower velocity signals, the wall filter helps to clean up the Doppler signal and reduce clutter, allowing for a clearer and more accurate display of blood flow velocities.

References

ARDMS Sonography Principles and Instrumentation (SPI) Exam Study Guide

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

Comprehensive and Detailed Explanation From Exact Extract:

Lateral resolution is the system’s ability to distinguish two structures side-by-side. It is directly determined by the beam width — the narrower the beam, the better the lateral resolution.

Principles and Instrumentation:

"Lateral resolution depends on beam width at a given depth. Narrower beams provide better lateral resolution."

Depth of penetration influences maximum imaging depth.

Propagation speed is largely constant in soft tissue.

Wavelength affects axial resolution.

Therefore, the correct answer is A: Beam width.

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The frame rate in color flow imaging is influenced by several factors, one of the most significant being line density. Line density refers to the number of ultrasound lines used to create an image. Increasing line density improves spatial resolution but requires more time to acquire each frame, thereby reducing the frame rate. Other factors such as filter selection, dynamic range, and variance map selection can affect the quality of the color flow image, but they do not have as direct an impact on frame rate as line density does.