The type of artifact that produces a reduction in echoes distal to a highly reflective or highly attenuating structure is 

Flow increases if _________________ increase(s).

Which of the following terms describes the change in direction of an ultrasonic beam when it passes from one medium to another in which elasticity and density differ from those in the first medium? 

If Doppler angle is doubled, the Doppler shift is 

The maximum Doppler shift frequency that can be sampled without aliasing is called 

Frame rate is determined by penetration depth and: 

In a stenosis, the pressure is ____________ the proximal and distal values.

Color Doppler imaging is a term used to describe 

The Doppler shift is the difference between __________ and ______________ frequencies.

Duplex imaging combines gray scale with Doppler and can appear as