ARDMS SPI MCQ 3

Question 1

What happens to the ultrasound beam at an interface where the angle of incidence equals the critical angle?

Accepted Answer

Refraction bends the beam to 90°

Answer

At the critical angle, refraction causes the transmitted beam to travel along the interface at 90°, and total internal reflection occurs.

Question 2

Which Doppler mode provides the best sensitivity for detecting slow-flow states such as organ perfusion?

Accepted Answer

Power Doppler

Answer

Power Doppler displays the amplitude (power) of the Doppler signal and is more sensitive to slow flow than color or pulsed wave Doppler.

Question 3

In B-mode imaging, increasing the time gain compensation (TGC) at depth primarily compensates for:

Accepted Answer

Attenuation of the ultrasound beam

Answer

TGC amplifies returning echoes from deeper structures to compensate for the progressive attenuation of the beam as it travels through tissue.

Question 4

A resistive index (RI) value close to 1.0 in a renal artery waveform suggests:

Accepted Answer

Absent or reversed diastolic flow

Answer

An RI near 1.0 indicates minimal or absent end-diastolic flow, suggesting markedly elevated distal resistance.

Question 5

Which statement best describes lateral resolution in ultrasound?

Accepted Answer

It is determined by beam width perpendicular to the beam axis

Answer

Lateral resolution depends on beam width; the narrower the beam at a given depth, the better the lateral resolution.

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test