Reverse chapter 15 Flashcards Preview

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Flashcards in Reverse chapter 15 Deck (50):
1

2 shades; black and white High Contrast

Bistable

2

Multiple levels of gray Low Contrast

Gray Scale

3

"real world" numbers unlimited # of choices continuous values

Analog

4

"computer" numbers limited choices discrete values

Digital

5

determines the range of brilliance within the displayed image

Contrast

6

determines the range of the displayed image

Brightness

7

translates the information from the spoke format into the video format

Scan convertor

8

image detail

Spatial resolution

9

image fade image flicker instability deterioration

Disadvantages of analog scan convertors

10

Uniformity Stability Durability Speed Accuracy

Advantages of digital scan convertors

11

smallest building block of a digital picture

Pixel

12

Number of picture elements per inch

Pixel Density

13

few pixels per inch larger pixels less detailed image lower spatial resolution

Low Pixel Density pixels per inch size of pixels detail of image spatial resolution

14

many pixels per inch smaller pixels more detailed image higher spatial resolution

High Pixel Density pixels per inch size of pixels detail of image spatial resolution

15

smallest amount of computer memory

Bit

16

group of eight bits of computer memory

Byte

17

computer memory consists of two bytes or 16 bits

Word

18

gray shades

Contrast Resolution

19

fewer shades of gray degraded contrast resolution

Fewer Bits per Pixel shades of gray contrast resolution

20

more shades of gray improved contrast resolution

More Bits per Pixel shades of gray contrast resolution

21

2^ number of bits

Calculating the shades of gray

22

image element image detail spatial resolution

Pixels vs Bits Pixel

23

computer memory gray shades contrast resolution

Pixels vs Bits Bits

24

Analog -> analog to digital converter -> Digital memory -> digital to analog converter -> Analog

Analog to digital converter

25

manipulating before storage in the scan convertor TGC log Compression write magnification persistence spatial compounding edge enhancement fill-in interpolation

Preprocessing

26

manipulating after storage in the scan convertor any change after freeze frame black/white inversion read magnification contrast variation 3-D rendering

Postprocessing

27

uses old data postprocessing larger pixel size same # of pixels as in the original ROI unchanged spatial resolution unchanged temporal resolution

Read Magnification

28

acquires new data preprocessing identical pixel size more pixels that in the original ROI improves spatial resolution may improves temporal resolution

Write Magnification

29

method of improving image quality

Coded Excitation

30

higher signal to noise ratio improved axial resolution improved spatial resolution improved contrast resolution deeper penetration

Advantages of Coded Excitation

31

reduces shadowing

Spatial Compounding

32

reduce speckle and noise artifact

Frequency Compounding

33

makes image look sharper

Edge Enhancement

34

makes image smoother "super impose"

Temporal Compounding or Persistence

35

predicts what information lies between the gaps and improves spatial resolution

Fill-in Interpolation

36

measure how dense something is and have mechanical properties

Elastography

37

Picture Archiving and Communications System Stored digitally

PACS

38

Digital Imaging and Computers in Medicine set of rules, or protocols, that allows imaging system to share info on a network

DICOM

39

charts from pen writers

Recording and Archiving Techniques: Paper Media Examples

40

portability does not require a device to read

Recording and Archiving Techniques: Paper Media Advantages

41

bulky, hard to store difficult to make copies cant display dynamic images

Recording and Archiving Techniques: Paper Media Disadvantages

42

computer discs computer memory magnetic tape video tape

Recording and Archiving Techniques: Magnetic Media Examples

43

able to store large amounts of info efficiently can store and play dynamic can record color

Recording and Archiving Techniques: Magnetic Media Advantages

44

can be erased by strong magnetic fields

Recording and Archiving Techniques: Magnetic Media Disadvantages

45

photographs flat films multiformat camera film

Recording and Archiving Techniques: Chemically Mediated Photographs Examples

46

High resolution accepted in the medical community can produce color images

Recording and Archiving Techniques: Chemically Mediated Photographs Advantages

47

bulky, difficult to store and retrieve requires chemical processing artifacts can arise from dirt pr chemical contamination

Recording and Archiving Techniques: Chemically Mediated Photographs Disadvantages

48

laser discs compact discs

Recording and Archiving Techniques: Optical Media Examples

49

store huge amounts of data inexpensive not erased by exposure to magnetic field

Recording and Archiving Techniques: Optical Media Advantages

50

requires a display system no standardized format for image display and storage

Recording and Archiving Techniques: Optical Media Disadvantages