CCI Ultrasound Physics and Instrumentation 2

Question 1

Which property of ultrasound determines the maximum depth of penetration in tissue?

Accepted Answer

Frequency

Answer

Lower frequencies penetrate deeper because attenuation increases with frequency, so lower frequencies lose less energy per unit depth.

Question 2

The term 'acoustic impedance' is defined as the product of:

Accepted Answer

Density and propagation velocity

Answer

Acoustic impedance (Z) equals tissue density (ρ) multiplied by the speed of sound (c) in that medium, expressed as Z = ρc.

Question 3

What artifact occurs when a strong reflector causes repeated echo returns at equally spaced intervals?

Accepted Answer

Reverberation artifact

Answer

Reverberation artifacts occur when sound bounces repeatedly between two strong reflectors, creating equally spaced false echoes at multiples of the true depth.

Question 4

In pulsed wave Doppler, the Nyquist limit determines the maximum:

Accepted Answer

Velocity that can be accurately measured without aliasing

Answer

The Nyquist limit is half the pulse repetition frequency; velocities causing Doppler shifts exceeding this value will alias and display incorrectly.

Question 5

Which mode of echocardiography provides the highest temporal resolution for cardiac motion analysis?

Accepted Answer

M-mode

Answer

M-mode records a single line of information at a very high frame rate (typically 1,000 frames/sec), providing superior temporal resolution for cardiac motion.

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI Ultrasound Physics and Instrumentation 2