Reverse chapter 15 Flashcards Preview

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Flashcards in Reverse chapter 15 Deck (50)
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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