The Doppler shift frequency is 

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

A study designed to determine if there is an association between an adverse effect in a population and an exposure to a particular agent is a(n):

Which of the following typically has the highest output intensity?

What is the first thing you should do when a patient enters the ultrasound room? 

What is the name of the mechanism of ultrasound bioeffects in which microbubbles oscillate without collapsing? 

An example of an acoustic window is 

Ultrasonic waves are 

As frequency increases, penetration will 

What determines the frequency of the transducer?