Enhancement is caused by 

The amount of dispersion in the far field of an ultrasound beam can be decreased by

Improper location of an echo may be attributable to

A shortened spatial pulse length results in 

What type of noise is associated with Doppler shift? 

What ultrasound method requires two active elements mounted side by side? 

A curving vessel within a color-flow image shows color in the vessel when the beam and vessel are parallel but shows no color, as the vessel turns perpendicular to the beam. The loss of color means that 

When the speed of fluid is constant across a vessel, the flow is called _________ flow.

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

If Doppler angle is doubled, the Doppler shift is