Ch 13

Question 1

Static Imaging

Answer 1

images displayed one frame at a time

“picture”

Question 2

Real Time Imaging

Answer 2

each frame is created and displayed very quickly, providing the impression of constant motion

“movie”

Question 3

Duplex Imaging

Answer 3

real time imaging and Doppler at same time

Question 4

Frame rate

Answer 4

system’s ability to create numerous frames each second

Question 5

Two things that determine frame rate

Answer 5

speed of sound in medium

depth

Question 6

Units of frame rate

Answer 6

Hz

Question 7

Temporal Resolution

Answer 7

ability to precisely position moving structures from instant to instant

Question 8

Speed is a fundamental limition of what?

Answer 8

temporal resolution

Question 9

4 factors that affect temporal resolution

Answer 9

1. depth
2. focus
3. Sector Size
4. Line Density

Question 10

If shallower or fewer pulses

go return time
t frame
frame rate
temporal resolution

Answer 10

short go-return time
shorter t frame
higher frame rate
superior temporal resolution

Question 11

If deeper or more pulses

go return time
t frame
frame rate
temporal resolution

Answer 11

long go-return time
longer t frame
lower frame rate
inferior temporal resolution

Question 12

t frame

Answer 12

time for one frame to be created

Question 13

t frame and frame rate relationship

Answer 13

inversely related

Question 14

pulses x PRP =

Answer 14

t frame

Example:

100 x 1/1000 second = 1/10 second or 10 Hz

Question 15

Factors Determining number of pulses per frame

Answer 15

number of focal points
sector size
line density

Question 16

Imaging depth and frame rate are what related?

Answer 16

Inversely

Question 17

Pulse per frame and frame rate are what related?

Answer 17

inversely

Question 18

Single Focus

pulses per frame
t frame
frame rate
temporal resolution
lateral resolution

Answer 18

one pulse per scan line
shorter t frame
higher frame rate
better temporal resolution
poorer lateral resolution

Question 19

Multi-focus

pulses per frame
t frame
frame rate
temporal resolution
lateral resolution

Answer 19

many pulses per scan line
longer t frame
lower frame rate
dimished temporal resolution
improved lateral resolution

Question 20

Frame rate and time are what related?

Answer 20

inversely related

Question 21

t frame x frame rate =

Answer 21

1

Example:

1/10 of a second, frame rate = 10 frames/second or 10 Hz

Question 22

Narrow Sector

pulses per frame
t frame
frame rate
temporal resolution

Answer 22

fewer pulses per frame
shorter t frame
higher frame rate
superior temporal resolution

Question 23

Wide Sector

pulses per frame
t frame
frame rate
temporal resolution

Answer 23

more pulses per frame
longer t frame
lower frame rate
inferior temporal resolution

Question 24

how to change sector size?

Answer 24

field of view

Question 25

Triplex Imaging

Answer 25

Pulse Waves, Color Doppler and real time imaging

Question 26

Low Line Density ``` spaced line pulses per frame t frame frame rate temporal resolution spatial resolution ```

Answer 26

``` widely spaced line fewer pulses per frame shorter t frame (faster) higher frame rate high temporal resolution poor spatial resolution ```

Question 27

High Line Density ``` spaced line pulses per frame t frame frame rate temporal resolution spatial resolution ```

Answer 27

``` tightly packed line more pulses per frame longer t frame lower rate rate lower temporal resolution excellent spatial resolution ```

Question 28

What is line density?

Answer 28

alter the spacing between sound beams

Question 29

Better Temporal ``` Resolution depth focus sector density frame rate ```

Answer 29

``` shallow imaging single focus narrow sector low line density higher frame rate ```

Question 30

Worse Temporal ``` Resolution depth focus sector density frame rate ```

Answer 30

deep imaging multiple focal points (improves lateral resolution) wide sector high line density (improves spatial resolution) lower frame rate

Question 31

Image vs movie quality

Answer 31

Some system settings produces an excellent photograph are inconsistent with producing an excellent movie. A low frame rate and poor temporal resolution create a great image but a poor movie