Bioeffects

Question 1

Small transducer that measures the characteristics of a sound beam. It is similar to a small hypodermic needle with a tiny piece of pieoelectric materal on the end

Answer 1

Hydrophone / microprobe

Question 2

What proposes that bioeffects result from tissue temperature evaluation

Answer 2

Thermal mechanism

Question 3

two bioeffect mechanisms

Answer 3

Thermal and cavitation

Question 4

TIS is

Answer 4

Soft tissue thermal index. Sound traveling in soft tissue

Question 5

TIB is

Answer 5

Bone thermal index. Assumes that bone is at or near the focus of the sound beam

Question 6

TIC is

Answer 6

Cranial bone thermal index. Assumes that cranial bone is in the sound beams near field

Question 7

The study of characteristics, attributes, and quantities of a substance that induces bioeffects is called

Answer 7

Dosimetry

Question 8

T/F there are no bioeffects in us

Answer 8

False

Question 9

T/F there are no harmful bioeffects associated with us

Answer 9

True

Question 10

A combo of __ and __ determine the likelihood of harmful bioeffects

Answer 10

temperature and exposure time

Question 11

Maximal heating is related to the beams

Answer 11

SPTA intensity

Question 12

Nonthermal or mechanical mechanisms consist of

Answer 12

Cavitation and radiation force

Question 13

Two forms of cavitation

Answer 13

Stable and transient

Question 14

Interaction of sound waves with microscopic gas bubbles in tissues. Also described as the creation of gaseous nuclei from dissolved gases in a fluid

Answer 14

Cavitation

Question 15

Lower MI levels and do not burst

Answer 15

Stable

Question 16

Higher MI levels, bubble bursting

Answer 16

Transient

Question 17

Transient is also called

Answer 17

Normal and inertial cavitation

Question 18

Stable cavitation have

Answer 18

microstreaming and shear stresses

Question 19

Lower MI means ___ cavitation, ___ pressure, and ___ frequency

Answer 19

less, less, higher

Question 20

Which modality is associated with the lowest tissue temp evaluation

Answer 20

Gray scale imaging

Question 21

Which modality is associated with highest tissue temp evaluation

Answer 21

Pulsed doppler

Question 22

Which component of an us system is most likely to expose a patient to danger

Answer 22

Transducer

Question 23

What is an appropriate use of us in ob

Answer 23

Provide medical benefit to the patient

Question 24

Unfocused or focused sound beams are less likely to create bioeffects because the beam will strike less gas bubbles

Answer 24

Focused

Question 25

The upper limit for the SPTA inensity of a focused us wave where there have been no observed bioeffects is

Answer 25

1 W/cm2

Question 26

What is the highest SPTA intensity of an unfocused ultrasound wave where there have been no observed bieffects

Answer 26

100 mW/cm2

Question 27

What has the highest mechanical index

Answer 27

low frequency, high pressure

Question 28

What us beam is more likely to cause temp elevation in soft tissue

Answer 28

unfocused

Question 29

What is considered the most important for a sonographer to decrease the liklihood of bioeffects

Answer 29

Duration of the study

Question 30

What devices convert us energy into heat

Answer 30

calorimeter and thermocouple