ARDMS SPI Exam Dumps

Temporal resolution refers to the ability to accurately depict moving structures over time.

A narrow sector width reduces the area being scanned, which increases the frame rate because fewer scan lines are required per frame.

Higher frame rates improve temporal resolution, allowing for better visualization of fast-moving structures.

Other factors like scan depth and the number of focal zones also affect frame rate but typically reduce it when increased, thereby decreasing temporal resolution. Reference:

ARDMS Sonography Principles and Instrumentation guidelines on factors affecting temporal resolution and frame rate.

Comprehensive and Detailed Explanation From Exact Extract:

Persistence is a frame averaging function that combines multiple sequential frames to smooth random noise and reduce speckle, particularly effective in stationary or slow-moving structures.

According to official Principles and Instrumentation guidelines:

'Persistence reduces random noise by averaging multiple frames over time, improving image clarity but potentially reducing temporal resolution.'

Increasing frequency improves resolution but may increase attenuation.

Sector width affects frame rate.

Depth affects penetration but not noise reduction.

Therefore, the correct answer is D: Persistence.

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Comprehensive and Detailed Explanation From Exact Extract:

Lateral resolution is determined by the beam width perpendicular to the ultrasound beam's axis. As depth increases, the beam width changes due to beam divergence after the focal point. Narrower beams (better focusing) provide improved lateral resolution at specific depths.

According to sonography instrumentation reference:

''Lateral resolution depends on the width of the ultrasound beam. The narrower the beam at a particular depth, the better the lateral resolution.''

Therefore, the correct answer is A: Beam width.

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Axial resolution refers to the ability to distinguish two structures that are close to each other along the path of the ultrasound beam.

Spatial pulse length (SPL) is the distance over which one pulse occurs, and it directly affects axial resolution.

Shorter SPL improves axial resolution because it allows better differentiation of closely spaced structures.

The axial resolution is improved by increasing the frequency of the transducer, which shortens the wavelength and hence the SPL. Reference:

ARDMS Sonography Principles and Instrumentation guidelines on resolution parameters and their impact on image quality.

Comprehensive and Detailed Explanation From Exact Extract:

Compression reduces the dynamic range of the returning echoes, which alters how many shades of gray are displayed. It compresses the range of signal amplitudes to fit into the grayscale display range.

According to sonography instrumentation reference:

''Compression alters the dynamic range, adjusting how many shades of gray are displayed to optimize image contrast.''

Therefore, the correct answer is B: The shades of gray displayed.

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