Imaging Processing and displays Flashcards Preview

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Flashcards in Imaging Processing and displays Deck (59):
0

What does the image processor do?

converts or processes the data

(voltages have been changed) in prep for display

1

What is the Scan Converter?

changes the US format (spokes) into TV format (interlaced) to make an image...now we can see it

2

What is the role of the scan converter?

image storage or memory

makes gray scale displays and real time imaging possible by **storing the image data**

3

What reformats echo data into image form for image processing, storage and display?

scan converter

4

Before computers what kind of scan converter did you have?

analog

now we have DIGITAL

5

What is performed on the image as part of the scan conversion?

preprocessing

6

Preprocessing is done BEFORE....

storage

7

What happens in the machine before storage in the preprocessing?

pixel interpolation

persistence

panoramic imaging

finish slide 13

8

What is pixel interpolation?

preprocessing

assigns a brightness value to a missed pixel

filling in missing pixels before it stores it

9

What is Persistence (frame averaging)?

preprocessing

averaging of sequential frames from the same view for a smoother appearance and NOISE reduction

***increase signal to noise ratio***

IMPROVES CONTRAST RESOLUTION

not used for rapid structures - heart

10

What is panoramic imaging?

preprocessing

makes it wider than normal

11

what is spatial compounding?

preprocessing

a method and an apparatus for **spatially compounding**US frames by using multiple angle views. (averaging at an angle)

successive image frames of a pixel data are processed using a SUM OF ABSOLUTE DIFFERENCE registration algorithm.

12

When frames are averaged and the anatomy is viewed from different angles, what is this called?

spatial compounding

13

what does edge enhancement do?

sharpens and defines boundaries

improved clarity

14

What is 3D imaging?

preprocessing

volume imaging

volume acquisition

15

What is elastography?

preprocessing

estimates tissue stiffness

16

Is TGC a preprocessing thing?

yes

comprises a TGC curve generator and the ability to drive the TGC curve generator to provide digital generation of the TGC curve

17

What is Write Magnification or Zoom (RES)?

preprocessing

rescans of the region of interest and creates a new image with improved spatial resolution

basically zoom

18

What is Log compression?

preprocessing

the max dynamic range the eye can see

19

What is the memory?

digital storage

image data converted to numbers

numbers stored in memory

numbers processed into an image

20

What is a pixel?

picture element

smallest element of a digital picture

(divide picture into a grid, each square is a pixel)

21

More pixels = best __________ ____________

spatial resolution

22

What is a matrix?

a board divided into pixels

the more pixels in the matrix the better the spatial resolution of the image

23

What is a BIT?

binary digit

smallest amount of digital storage

24

Binary numbers are based on 2...all numbers consist of what numbers?

0 and 1

25

If you have 8 bits how many shades of gray?

2 to the 11th power = 254

26

if you have low bits and low shades of gray which equals high contrast imaging....what kind of imaging are you doing?

cardiac and vascular

27

if you increase the gray mapping what are you imaging?

^bits and ^shades of gray = low contrast imaging for abd, OB, and superficial

28

post processing is done AFTER

storage

29

What is Read magnification?

post-processing

occurs after the data is stored

number of pixels the same

does not improve resolution just makes it larger

30

What is black and white inversion?

simply inverting black things to white and white to black

31

What is the display

the link between the system and the sonographer

makes a visual picture

32

What are the old kind of displays?

CRT - cathode Ray Tube (like and old TV)

has ELECTRONS sweep across the face of the screen

and those hit the PHOSPHOR

then it glows and turns electrons into light

brightness of the echo is seen on the display

33

What is a raster scan?

it's the moving of the electrons across the monitor

to make a picture on the old CRT display

34

The CRT used _______ display

interlaced

525 closely spaced horizontal lines

odd field and even field are laced together to make a frame

frame rate is 30Hz

35

What are the three colors for the electron in the CRT?

Red, Blue, Green cathodes

36

The new displays have what kind of screen?

flat panel

advantages:

HIGHER FRAME RATE

lighter weight

slim profile

less power consumption

less heat generation

37

What is bistable? (old display)

only two choices - white or black, off or on

high contrast image

narrow dynamic range

38

What are the controls on the display? (new display)

brightness (determined the brilliance of the signals displayed)

contrast (determines the range of brightness that is displayed)

39

on the new displays, what is gray scale - gray mapping?

levels of brightness

assignment of different shades of gray for each echo amplitude

dynamic range

low contrast image

40

how is digital generation of the time gain compensation curve achieved?

by an initial gain and data represented by a series of SLOPES and associated TIME-DEPENDENT break-points

41

Pixel density =?

pixels per inch

42

WHat is the ability to observe subtle echo strength difference between adjacent tissue?

contrast resolution

43

What is the operator controlled after the image is stored adjustments called?

post processing

44

What ways can we manipulate the image data after storage?

read magnification

black/white inversion

B-color

3-D rendering

45

What is B color?

post processing

echoes in various colors rather than gray

improved contrast resolution

46

What is surface rendering?

Three dimensional imaging (aka 4D when you watch in real time 3D)

47

What are the differences between analog and digital display?

Analog digital

real world computer world
actual measuring discrete
continuous
unlimited choices limited choices

48

if you change the image display on one monitor does it change another image display on a different monitor?

no

49

What are all of parts of the system in order of their job?

master > beam former > receiver > Image processing > scan converter (preprocessing) > digital storage (post processing)>>>display

50

The beam scanned...analog or digital?

echoes received, converted to numbers...analog or digital?

Analog

digital

51

What are the different ways of recording and archiving?

Paper (what we give for anatomy pics)

Magnetic

chemically media

magnet-optical

52

What was the problem with magnetic recording and archiving?

disrupted by strong magnetic field

Video tapes, cassette tapes...erased if near magnetic field

53

what was the problem with chemically media recording and archiving?

wrong temp, contaminated chemicals

way back when sonographers needed to print films of their studies

54

What is the advantages of magneto-optical recording and archiving?

CD's

magnetic and laser technology

huge capacity for storage

protected data

time required to locate and mount disk

55

What are our options for image recording an archiving in a digital world?

Image files

JPEG (joint photographic experts group)

TIFF (tagged image file format)(larger but better quality)

MPEG (moving picture experts group)

AVI (audio video interleave)

56

What is PACS?

picture archiving and communication system (physical network)

57

What are the pros and cons of PACS?

computer network - digital retraining

expensive

send anywhere

58

What is DICOM

Rules allowing communication

digital imaging and communication in medicine