SPI Module 9 Bioeffects & Safety

Question 1

The acoustic variable defined as force divided by area is called:

1. intensity
2. joule
3. Pascal
4. pressure

Answer 1

4

Question 2

The amount of power divided by area is called:

Answer 2

intensity

Question 3

To reduce the acoustic exposure to the patient, the sonographer should:

1. decrease the output control
2. decrease the receiver gain
3. increase the output control
4. increase the receiver gain

Answer 3

1

Question 4

If the power is doubled, the intensity will be….

Answer 4

doubled

Question 5

If the amplitude is doubled, the intensity will….

Answer 5

increase by a factor of 4 (quadrupled)

Question 6

Which of the following units are used to measure intensity?

1. milliwatts per centimeter
2. milliwatts per centimeter squared
3. watts per centimeter
4. watts per meter squared

Answer 6

2

Question 7

The instrument that measures the intensity of the sound beam is a:

Answer 7

hydrophone

Question 8

Experiments performed in petri dishes are called:

Answer 8

in vitro

*note: in vivo - in a living thing i.e. animal

Question 9

Which of the following is used to measure the MI of the sound beam?

1. sound interaction with gas bodies
2. attenuation properties of tissue and thermal properties
3. absorption rate within tissue
4. frequency, power, beam area, and absorption rate within tissue

Answer 9

1

Question 10

Which of the following intensities is measured during the pulse repetition period?

1. SATP
2. SPTA
3. SATA
4. SATP

Answer 10

3