Kremkau Chapter 7 Key Terms

Question 1

ALARA

Answer 1

as low as reasonably achievable. the principle that it is prudent to obtain diagnostic information with the least amount possible of energy exposure to the patient.

Question 2

cavitation

Answer 2

production and dynamics of bubbles in sound

Question 3

hydrophone

Answer 3

a small transducer element mounted on the end of a narrow tube; a piezoelectric membrane with small metallic electrodes.

Question 4

mechanical index

Answer 4

an indicator of nonthermal mechanism activity; equal to the peak rarefactional pressure divided by the square root of the center frequency of the pulse bandwidth.

Question 5

phantom

Answer 5

tissue equivalent device that has characteristics that are representative of tissues.

Question 6

polyvinylidene fluoride

Answer 6

a piezoelectric thin film material.

Question 7

radiation force

Answer 7

the force exerted by a sound beam on an absorber or a reflector.

Question 8

test object

Answer 8

a device without tissue like properties that is designed to measure some characteristic of an imaging system.

Question 9

thermal index

Answer 9

an indicator of thermal mechanism activity; a valve equal to transducer acoustic output power divided by the estimated power required to raise tissue temperature by 1 degree Celsius.