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 

Both the color and a point spectrum in a stenosis show high-frequency aliasing.  One strategy for removing the aliasing involves 

The Doppler shift frequency is 

Tissue-equivalent phantoms attempt to represent some acoustic property of ______________.