CCI Ultrasound Physics and Instrumentation 4

Question 1

The piezoelectric effect in ultrasound transducers refers to:

Accepted Answer

Conversion of electrical energy to mechanical vibration and vice versa

Answer

Piezoelectric crystals deform mechanically when voltage is applied (transmit) and generate voltage when mechanically deformed by returning echoes (receive).

Question 2

Increasing the gain on an ultrasound system primarily affects:

Accepted Answer

The amplification of returning echo signals

Answer

Gain uniformly amplifies all returning echo signals electronically without changing transmission power or depth penetration.

Question 3

Which Doppler equation component must the sonographer manually align to minimize velocity measurement error?

Accepted Answer

Doppler angle (θ)

Answer

Velocity = (Doppler shift × c) / (2 × frequency × cos θ); the angle θ must be estimated and corrected by the operator to calculate true velocity.

Question 4

A spectral Doppler waveform showing systolic flow above and diastolic flow below the baseline in an arterial study most likely indicates:

Accepted Answer

Bidirectional flow with forward systole and reverse diastole (triphasic pattern)

Answer

A triphasic arterial waveform shows rapid systolic forward flow, brief early diastolic flow reversal, and then slow antegrade late diastolic flow, characteristic of normal peripheral arteries.

Question 5

The axial resolution of an ultrasound system is best improved by:

Accepted Answer

Shortening pulse duration (using higher frequency or damped transducers)

Answer

Axial resolution = spatial pulse length / 2; shorter pulses achieved with higher frequencies or heavy damping allow discrimination of closely spaced objects along the beam axis.

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI Ultrasound Physics and Instrumentation 4