Chapter 13 Real-Time Imaging

Question 0

Ability of the system to create numerous frames per second is called?

Answer 0

Frame rate

Question 1

Images displayed one image at a time in the early days was known as?

Answer 1

Static scanning

Question 2

Factors affecting frame rate include

Answer 2

• speed of sound in the medium

- imaging depth

Question 3

What unit is frame rate measured in?

Answer 3

Hertz (images per second)

Question 4

What does “accuracy in time” (the ability to precisely position moving structures from instant to instant) describe?

Answer 4

Temporal resolution

Question 5

Temporal resolution is excellent when a system produces __________ frames per second.

Answer 5

Many

Question 6

Temporal resolution is determined by?

Answer 6

Frame rate

Question 7

High frame rate will ________ temporal resolution.

Answer 7

Improve

Question 8

What are the units for temporal resolution?

Answer 8

Hertz (per second)

Question 9

What is the relationship between frame rate and the time required to make a single image?

Answer 9

Inversely related and reciprocals

Question 10

Two sonographer-controlled settings of an ultrasound system determine frame rate:

Answer 10

1. Imaging depth

2. Number of pulses per frame

Question 11

Imaging depth and frame rate are directly or inversely related?

Answer 11

Inversely related

Question 12

Shallow imaging increases frame rate and does what to temporal resolution?

Answer 12

Improves

Question 13

Deeper imaging decreases frame rate and does what to temporal resolution?

Answer 13

Degrades

Question 14

High frame rate equals _________ depth

Answer 14

Shallow

Question 15

Low frame rate equals _______ depth

Answer 15

Deep

Question 16

The following describes what type of imaging:

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

Answer 16

Shallow imaging

Question 17

The following describes what type of imaging depth:

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

Answer 17

Deep imaging

Question 18

What’s the equation for time needed to make a single frame?

Answer 18

Tframe = # pulses x PRP

Question 19

Pulses per frame and frame rate are directly or inversely related?

Answer 19

Inversely related

Question 20

What is needed to give the illusion of moving pictures?

Answer 20

High frame rate

Question 21

What factors affect the number of pulses needed to create an image?

Answer 21

• number of focal points
• sector size
• line density

Question 22

What type of focus is describe below:

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

Answer 22

Single focus

Question 23

What type of focus is described below:

• many pulses per scan line
• longer Tframe
• lower frame rate
• diminished temporal resolution
• improved lateral resolution

Answer 23

Multi-focus

Question 24

What is the main advantage of multiple focal zones?

Answer 24

It improves accuracy in the individual images, each scan line has better lateral resolution because it is narrow over a wide range if depths

Question 25

Field of view (sector size) and frame rate are directly or inversely related?

Answer 25

Inversely related

Question 26

Narrower images result in ______ frame rates. Wider images result in _______ frame rate.

Answer 26

Higher; lower

Question 27

- fewer pulses per frame - shorter Tframe - higher frame rate - superior temporal resolution These describe what type of sector?

Answer 27

Narrow sector

Question 28

- more pulses per frame - longer Tframe - lower frame rate - inferior temporal resolution These describe what type of sector?

Answer 28

Wide sector

Question 29

Ultrasound systems can alter the spacing between sounds beams and this is known as?

Answer 29

Line density

Question 30

Lines that are spaced far apart is?

Answer 30

Low line density

Question 31

Lines closely packed is called?

Answer 31

High line density

Question 32

Line density and frame rate are directly or inversely related?

Answer 32

Inversely related

Question 33

- widely spaced lines - fewer pulses per frame - shorter Tframe - higher frame rate - high temporal resolution - poor spatial resolution This describes what type of line density?

Answer 33

Low line density

Question 34

- tightly packed lines - more pulses per frame - longer Tframe - lower frame rate - low temporal resolution - excellent spatial resolution Describes what type of line density?

Answer 34

High line density

Question 35

What is the main advantage of high line density?

Answer 35

Improved spatial (detail) resolution

Question 36

Lateral resolution improves with _________ focusing.

Answer 36

Multi

Question 37

Spatial resolution improves with _______ line density

Answer 37

Higher

Question 38

- shallower imaging - single focus - narrow sector - low line density Describes what type of frame rate?

Answer 38

Better-higher frame rate

Question 39

- deeper imaging - multiple focal points (improves lateral resolution) - wide sector - high line density (improves spatial resolution) Describes what type of frame rate

Answer 39

Worse-lower Frame rate

Question 40

Temporal resolution is directly or inversely related to frame rate?

Answer 40

Directly related