Ch.5 Intensities

Question 1

1. Intensities may be reported in various ways with respect to _____ and _____

Answer 1

time and space

Question 2

2. The different measurements of intensities are important in the study of _______

Answer 2

Bioeffects

Question 3

3. The units for all intensities are _____

Answer 3

Watts/cm^2

Question 4

4. Bc peak measurements are larger than average measurements, _ _ _ _ intensity has the highest value, and _ _ _ _ has the lowest value

Answer 4

SPTP
SATA

Question 5

5. A number called the ______ _______ ________ (also called _ _ / _ _ _____ ) describes the spread of a beam in space. It is unitless, with a value of _ or greater

Answer 5

Beam uniformly coefficient
SP/SA factor
1

Question 6

Beam uniformly coefficient describes what?

Answer 6

the spread of a beam in space. it is unitless with a value of 1 or greater

Question 7

6. The ____ ____ describes the relationship of beam intensities with time. It is unitless, with a value between _ and _

Answer 7

Duty Factor
0 and 1

Question 8

Duty Factor

Answer 8

describes the relationship of beam intensities

Question 9

7. For continuous wave ultrasound, the beam is always “__” and the pulse average and temporal average intensities are the _______. Thus,
   SPTA = _ _ _ _
   SATA = _ _ _ _

Answer 9

on
Same
SPTA = SPPA
SATA = SAPA

Question 10

8. When pulsed and continuous wave sound beams have the same SPTP intensities, the continuous wave beam has the _______ _ _ _ _ intensity

Answer 10

higher SPTA

Question 11

8. When pulsed and continuous wave sound beams have the same SATP intensities, the continuous wave beam has the _______ _ _ _ _ intensity

Answer 11

higher SATA

Question 12

9. Temporal Peak intensity (Itp) is ________ intensity in ______.

Answer 12

maximum
time

Question 13

9. Im intensity is averaged over the ______ ________ ____-____

Answer 13

most intense half cycle

Question 14

9. Pulse average intensity (Ipa) is averaged ONLY during the ____ _____

Answer 14

Pulse duration (“on” time)

Question 15

9. Temporal average intensity (Ita) is averaged during the ___

Answer 15

PRP (both the “on” and “off” times)

Question 16

10. Spatial peak intensity (Isp) is the _________ ___ ______

Answer 16

maximum in space

Question 17

10. Spatial average intensity (Isa) is averaged over the ____ ____ ___ __ ___ ____

Answer 17

cross-sectional area of the beam

Question 18

Rank Intensities from largest to smallest:
____–>____–>____–>____–>____

Answer 18

SPTP –> Im –> SPPA –> SPTA –> SATA

Question 19

Spatial

Answer 19

refers to distance or space. An ultrasound beam does not have the same intensity at different locations

Question 20

Temporal

Answer 20

refers to all time, transmit (pulse duration) and receive. A pulsed ultrasound beam does not have the same intensity at different times

Question 21

Pulsed

Answer 21

refers only to the transmit time (pulse duration). A pulsed beam does not have the same intensity at different times during the pulse.

Question 22

Pulsed is the

Answer 22

average intensity for the pulse duration ONLY

Question 23

Im or Imax

Answer 23

is the average intensity during the most intense half-cycle

Question 24

Temporal intensities from largest to smallest:
___ –> ___ –> ___–>___

Answer 24

Itp, I max, Ipa, Ita