Important ARDMS SPI Exam Questions

Answer: D

Explanation:

Comprehensive and Detailed Explanation From Exact Extract:

The matching layer is placed in front of the piezoelectric element and serves to reduce the difference in acoustic impedance between the transducer and human tissue, thereby improving sound transmission and minimizing reflection at the interface.

According to sonography instrumentation reference:

''The matching layer minimizes impedance mismatch between the transducer and soft tissue, allowing more efficient transmission of ultrasound energy into the patient.''

Therefore, the correct answer is D: Matching Layer.

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Answer: A

Explanation:

When utilizing multiple transmit focal zones, the ultrasound system must perform multiple transmissions at each focal depth. This process requires more time for data acquisition, which in turn decreases the frame rate. A lower frame rate directly impacts temporal resolution, which is the ability to accurately depict moving structures over time. Thus, using multiple focal zones improves lateral resolution but degrades temporal resolution. Reference:

American Registry for Diagnostic Medical Sonography (ARDMS) Sonography Principles and Instrumentation guidelines.

Answer: C

Explanation:

Comprehensive and Detailed Explanation From Exact Extract:

The image shows an area of signal dropout directly deep to the strongly reflecting structure (likely a vessel wall or calcification), indicated by the arrow. This is a classic example of shadowing artifact.

According to sonography Principles and Instrumentation:

'Shadowing occurs when a highly attenuating or reflective structure blocks the ultrasound beam, resulting in absence of signal distal to the object.'

Mirroring (A) produces duplicated structures.

Noise (B) appears as random speckles.

Enhancement (D) produces increased echogenicity distal to an anechoic structure.

Therefore, the correct answer is C: Shadowing.

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Answer: C

Explanation:

Comprehensive and Detailed Explanation From Exact Extract:

Aliasing happens in Doppler ultrasound when the Doppler shift frequency exceeds half of the pulse repetition frequency (the Nyquist limit). When PRF is too low for the measured Doppler shift, the signal wraps around, producing aliasing.

According to sonography instrumentation reference:

''Aliasing occurs when the Doppler shift frequency exceeds one-half the pulse repetition frequency (Nyquist limit). This results in incorrect display of flow direction and velocity.''

Therefore, the correct answer is C: Aliasing.

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Answer: B

Explanation:

Comprehensive and Detailed Explanation From Exact Extract:

Overall gain amplifies the strength of all returning echoes equally, regardless of depth. It does not affect the transmitted pulse or selectively compensate for attenuation; it simply amplifies received signals uniformly.

According to sonography instrumentation reference:

''Overall gain controls the amplification of all returning echoes across the entire image, increasing brightness uniformly at all depths.''

Therefore, the correct answer is B: Amplification of signals from all depths.

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