Krem Ch7

Question 1

ALARA

Answer 1

As low as reasonable achievable. The principle that is prudent to obtain diagnostic information with the least amount possible of energy and 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 to piezoelectric membrane with small metabolic electrodes.

Question 4

Mechanical index

Answer 4

An indicator of nonthermal mechanism activity, equal to the peak we fractional pressure divided by the square root of the center frequency of the pulse band width.

Question 5

Phantom

Answer 5

Tissue equivalent device that has characteristics that are representative of tissue, propagation speed, and attenuation.

Question 6

Polyvinylidene fluoride

Answer 6

A piezoelectric thin film material.

Question 7

Radiation force

Answer 7

The force exerted by a sound being on and absorber or reflector.

Question 8

Test object

Answer 8

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

Question 9

Thermal index

Answer 9

An indicator of thermal mechanism activity a value equal to transducer acoustic output power divided by the estimated power required to raise tissue temperature by 1°C.