Deck 7: Performance and Safety

Question 1

In soft tissue,a temperature rise is considered significant once it exceeds ________.

A) 2 °C
B) 4 °C
C) 2 °F
D) 4 °F

Answer 1

A
Temperature rises are considered significant if they exceed 2 °C.

Question 2

No bioeffects have been observed in mammalian tissues at mechanical index values of less than ________.

A) 0.4
B) 0.3
C) 0.2
D) 0.1

Answer 2

A
Tissues that contain well defined gas bodies (for example,lungs) have been observed for in situ peak rarefactional pressure below approximately 0.4 MPa or mechanical index values less than approximately 0.4.

Question 3

No bioeffects have been observed in mammalian tissues that contained well-defined gas bodies at peak rarefactional pressure values (MPa) of less than ________.

A) 0.4
B) 0.2
C) 0.3
D) 0.1

Answer 3

A
Tissues that contain well-defined gas bodies (for example,lungs) have been observed for in situ peak rarefactional pressure below approximately 0.4 MPa or mechanical index values less than approximately 0.4.

Question 4

Which of the following relates to heating?

A) Impedance.
B) Sound speed.
C) Distance from transducer.
D) Absorption.

Question 5

Which of the following describes cavitation?

A) Flow in an absorbing fluid.
B) Conversion of ultrasound to heat.
C) Temperature rise as ultrasound propagates through tissue.
D) Production and behavior of bubbles in a liquid medium.

Question 6

Which of the following is a biological consequence of hyperthermia?

A) Glaucoma.
B) Macrophthalmia.
C) Abdominal wall defects.
D) Multicystic renal disease.

Question 7

Bioeffects have not been observed in experimental animals with focused intensities below ________.

A) 1 mW/cm2 spatial peak-temporal average (SPTA)
B) 10 mW/cm2 SPTA
C) 1 mW/cm2 spatial peak-temporal peak (SPTP)
D) 10 mW/cm2 SPTP

Question 8

Test objects evaluate ________.

A) amplitude
B) detail resolution
C) dynamic range
D) temporal resolution

Question 9

Attenuation in soft tissue is due primarily to ________.

A) refraction
B) absorption
C) reflection
D) transmission

Question 10

The piezoelectric material commonly used in hydrophones is ________.

A) PVD
B) PVDF
C) PZT
D) PZTF

Question 11

Which of the following cannot be measured or calculated by a hydrophone?

A) Period.
B) Amplitude.
C) Impedance.
D) Pulse duration.

Question 12

Tissue-equivalent phantoms are filled with a substance containing ________.

A) water
B) quartz
C) silicone
D) graphite

Question 13

The American College of Radiology (ACR) Ultrasound Accreditation Program requires at least ________ testing for instrument quality control.

A) semimonthly
B) monthly
C) semiannual
D) annual

Question 14

The extent of temperature rise produced depends on

A) intensity and frequency
B) type of tissue and intensity
C) penetration depth and frequency
D) number of focal zones and intensity

Question 15

Biological effects have not occurred at temperatures lower than ________.

A) 39 °C
B) 42 °C
C) 39 °F
D) 42 °F

Question 16

Plant studies are useful primarily for ________.

A) identifying focal lesion production
B) understanding cavitational effects in living tissue
C) determining conditions under which thermal effects occur
D) determining conditions under which nonthermal effects occur

Question 17

Which of the following pulsed-wave techniques demonstrates the lowest sonographic output?

A) M (motion)-mode.
B) Gray-scale.
C) Color Doppler.
D) Spectral Doppler.

Question 18

Which of the following pulsed imaging techniques demonstrates the highest acoustic output?

A) Gray-scale.
B) Motion mode.
C) Color Doppler.
D) Spectral Doppler.

Question 19

Which of the following is not assessed with a tissue-equivalent (TE) phantom?

A) Penetration.
B) Beam width.
C) Dynamic range.
D) TGC operation.

Question 20

A significant increase in the temperature of tissues close to the transducer is a result of ________.

A) transducer self-heating
B) warm coupling medium
C) thickness of the element
D) propagation speed of the element

Question 21

Test objects are used by engineers rather than instrument operators.

Question 22

Doppler test objects and flow phantoms are not able to evaluate gate location.

Question 23

For exposure duration up to fifty hours,there have been no significant adverse biological effects observed from temperature increases £ 2 °C above normal.

Question 24

Ultrasound produces a temperature increase as it propagates through tissues.

Question 25

Bioeffects are useful in therapeutic applications of ultrasound.

Question 26

The as low as reasonably achievable (ALARA) principle regulates ultrasound instruments.

Question 27

A medical indication for a sonography examination is part of the as low as reasonably achievable (ALARA) principle.

Question 28

The output of some currently available diagnostic ultrasound devices can generate levels that produce hemorrhage in the lungs of laboratory animals.

Question 29

The American Institute of Ultrasound in Medicine (AIUM) strongly discourages nonmedical use of ultrasound.

Question 30

The spatial peak temporal peak (SPTP) intensity is used in the American Institute of Ultrasound in Medicine (AIUM) statement on mammalian bioeffects.