Chapter 3

Question 1

With standard ultrasonic imaging, what happens to the period of a wave as it propagates?

Question 2

What determines the period of an ultrasound wave?

Answer 2

The transducer

Question 3

Which of the following units are appropriate to describe the period of an acoustic wave?
A. Minutes
B. Microseconds
C. Meters
D. mm/us
E. Cubic centimeters

Answer 3

Minutes and microseconds

Question 4

T or F
The sonographer has the ability to alter the period of an ultrasound wave that is produced by a basic transducer.

Answer 4

False

Question 5

What term describes the number of cycles that an acoustic variable completes in a second?

Answer 5

Frequency

Question 6

What is the range of frequencies emitted by transducers used in ultrasonic imaging?

Answer 6

1 to 3 MHz

Question 7

What establishes the frequency of an ultrasound wave?

Answer 7

The transducer

Question 8

T or F
With standard ultrasound pulses, the frequency of the ultrasound wave changes significantly as the wave propagates through the body.

Question 9

When a sonographer increases the maximum imaging depth during an exam, what happens to the frequency?

Question 10

Infrasound is defined as a sound with a frequency of:

Answer 10

Less than 20 Hz

Question 11

T or F
Waves in the ultrasound range behave in the same general manner as sound waves that are audible

Question 12

What is characteristics of acoustic waves with frequencies exceeding 20,000 Hz when compared with waves having frequencies of less than 20,000 Hz?

Answer 12

They attenuate more when traveling in soft tissue

Question 13

T or F
If the periods of two waves are the same, then the frequencies of the waves must also be the same.

Question 14

Compared to sound waves, A and B. The frequency of a wave A is 1/3 that of wave B. How does the period of wave A compare with the period of wave B?

Question 15

The reciprocal of period is:

Answer 15

Frequency

Question 16

What determines the initial amplitude of an ultrasound wave?

Answer 16

The transducer

Question 17

As an ultrasound wave travels through the body, it’s amplitude usually:

Answer 17

Decreases

Question 18

The power of an ultrasound wave can be reported with which of the following units?

Answer 18

Watts

Question 19

Typically, as an ultrasound wave travels through soft tissue, the power of the wave:

Answer 19

Decreases

Question 20

Mathematically, when a number is squared, the number is multiplied by:

Answer 20

Itself

Question 21

The final amplitude of an acoustic wave is reduced to one-half of its original value. The final power is _________ the original power.

Question 22

The amplitude of an acoustic wave decreases from 27 pascals to 9 pascals. If the initial power was 27 watts, what is the waves final power?