image processor

Question 1

image processor includes?

Answer 1

• preprocessor
• scan converter
• image memory
• postprocessor
• digital-to-analog converter

Question 2

scan line info is?

Answer 2

• built into frames of information

- pre-processed

Question 3

scan conversion?

Answer 3

• done by scan conveter
• building a frame
• properly located each echo on image frame
• real time
• echo info (scan lines) to image form (frames)

Question 4

scan convertion how many scan lines in a frame?

Answer 4

96-256 scan lines in a frame

Question 5

Each frame is made up of a ‘matrix’ of tiny blocks called?

Answer 5

pixels

Question 6

typically pixels in a matrix?

Answer 6

• 1024 x 768

- 512 x 384

Question 7

3D =

Answer 7

voxels

Question 8

pre-processing?

Answer 8

• before freeze
• done while echo data is being stored in memory
• the frame is still being built during this time

Question 9

post-processing?

Answer 9

• freeze

- done on image retrieved from image memory

Question 10

prepocession characteristics? (6)

Answer 10

• before the data is stored in memory
• persistence
• panoramic
• 3D
• spatial compounding
• write magnification

Question 11

post processing characteristics? (6)

Answer 11

• after data is stored in image memory
• b colour
• freeze frame
• black/white image invention
• read magnification
• contrast variation

Question 12

what is edge enhancement?

Answer 12

• pre-processing

- sharpens boundaries to make them more detectable and make measurements more precise

Question 13

pixel interpolation aka?

Answer 13

• fill-in interpolation

- filling in missed pixels

Question 14

what is spacial compounding?

Answer 14

• hit the same object from different angles and average the images
• trying to hit structures at 90 degrees

Question 15

persistance?

Answer 15

• aks frame averaging
• averaging of sequential frames
• reduces noise

Question 16

persistance affects?

Answer 16

• better contrast resolution
• operator controlled
• decreased FR

Question 17

what is 4D imaging?

Answer 17

= 3D + time

Question 18

B- colour aka?

Answer 18

• tint/ colour scale

- chroma map

Question 19

the human eye can see how many shades of grey and colour?

Answer 19

100 shades of grey

256 shades of colour

Question 20

what is read magnification?

Answer 20

• pulls out specific pixels from the frame from memory and displays them using the entire display

Question 21

drawbacks of image processor?

Answer 21

• enlargement of pixels

Question 22

what is write magnificaiton?

Answer 22

• smaller field of view is written using pixels for entire frame
• better resolution

Question 23

image memory?

Answer 23

• aks digital memory

Question 24

what is freeze frame?

Answer 24

displays lastest image stored in memory

Question 25

what is cineloop?

Answer 25

displays last 100-130 images

Question 26

what does each pixel contain?

Answer 26

brightness (intesity/amplitude) at a particular anatomical position

Question 27

one matrix can show how many shades of grey?

Answer 27

2 (on and off)

Question 28

a 1-bit pixel is called?

Answer 28

bistable

Question 28

a 1-bit pixel is called?

Answer 28

bistable

Question 29

3 bit memory = how many shades of grey?

Answer 29

8

Question 30

what is a binary number system?

Answer 30

alternative to decimal (arabic) number system

Question 31

what is contrast resolution?

Answer 31

being able to seperate 2 different echoes as 2 different shades of grey

Question 32

1024 bytes =?

Answer 32

1 kilobyte

Question 33

display requires what kind of signals?

Answer 33

analog

Question 34

digital-to-analog converter?

Answer 34

Digital memory (#’s) - voltages for display

Question 35

frame rate?

Answer 35

of images stored in memory per second

Question 36

refresh rate?

Answer 36

of images displayed per second

Question 37

temporal resolution?

Answer 37

- ability of a display to distinguish closely spaced events in time and present rapidly moving structures correctly - Higher frame rate improves temp res

Question 38

temporal reolution- what does each from contain?

Answer 38

LPF- lines per frame | n- number of foci

Question 39

each focus and line require?

Answer 39

a pulse

Question 40

to increase the number of foci?

Answer 40

the PRF must increase

Question 41

to increase the number of lines per frame?

Answer 41

the PRF must increase

Question 42

to increase FR?

Answer 42

PRF must increase

Question 43

temporal resolution depends on?

Answer 43

- FR