Test 4

Question 0

Phosphor -

Answer 0

Europium barium fluorohalide crystals

Question 1

PSP/IP - Photostimulable Phosphor/Image Plate -

Answer 1

plate used in CR in place of film

Question 2

Anti-halo/Reflective -

Answer 2

Prevents laser light from penetrating; Allow reflected light from the phosphor to pass through.

Question 3

Conductive -

Answer 3

Removes static electricity

Question 4

Base -

Answer 4

PET - polyethylene terephthalate

Question 5

Backing -

Answer 5

Protects base from handling damage, contains bar code label on IR

Question 6

Europium Barium Fluorohalide -

Answer 6

X-ray energy enters these molecules, that energy is absorbed by the molecules

Question 7

F-centers -

Answer 7

Electrons elevated out of their normal orbital rings into higher orbitals.

Question 8

Fading -

Answer 8

The process of image weakening from latent image being stored on a cassette and not processed immediately.

Question 9

Readout -

Answer 9

Scan of phosphor plate with helium-neon laser light and reads the latent image from the phosphor.

Question 10

Raster -

Answer 10

A side to side pattern a laser uses to obtain an image.

Question 11

Helium-Neon laser - (HeNe) -

Answer 11

Type of laser light used to read the latent image from the phosphor

Question 12

Latent image -

Answer 12

the image held in the chemical code

Question 13

Digitizing -

Answer 13

the process of translating an analog image into a binary code

Question 14

Binary Code -

Answer 14

numerical code of digits 1 & 0’s that computers can see, process, and transfer information

Question 15

QDE - Quantum Detection Efficiency -

Answer 15

measures the efficiency of a CR system to convert remnant radiation into useful image signals

Question 16

Contrast resolution -

Answer 16

the ability to distinguish adjacent structures that have similar densities

Question 17

Exposure Indicators -

Answer 17

the amount of radiation received by the cr imaging plate

Question 18

Fuji - (the “s” number) -

Answer 18

the exposure indicator for Fuji brand

Question 19

Fuji - Expectation range

Answer 19

180-220

​

Question 20

Fuji - Perfect Exposure Indicator

Answer 20

200

Question 21

Fuji - Direct or Indirect relationship to dose -

Answer 21

indirect

Question 22

Kodak - (the “EI” number) -

Answer 22

exposure indicator number for Kodak

Question 23

Kodak - Expectation range:

Answer 23

1950-2050

Question 24

Kodak Perfect Exposure Indicator:

Answer 24

2000

Question 25

Kodak Direct or Indirect relationship to dose:

Answer 25

direct relationship

Question 26

Agfa - (the "LGM" number) -

Answer 26

The Agfa CR exposure indicator

Question 27

Agfa Expectation range:

Answer 27

1.9-2.5 LGM

Question 28

Agfa Perfect Exposure Indicator:

Answer 28

2.2 LGM

Question 29

Agfa Direct or Indirect relationship to dose -

Answer 29

direct relationship

Question 30

Quantum mottle -

Answer 30

Noise | Too few X-rays in the beam to adequately form an image

Question 31

Analog -

Answer 31

A device or system that represents information as continuously variable physical quantities. Like a mechanical watch. X-ray film is analog.

Question 32

Digital -

Answer 32

Device or system that represents information as continuously variable numerical values. Like a digital watch. CR & DR are digital.

Question 33

FPD - Flat Panel Detector (DR Imaging Plate) -

Answer 33

Takes the place of cassettes and readers; 3 different types: Tethered (w/cord) Fixed (mounted in Bucky) Wireless (uses radio signal sent from FPD to base)

Question 34

Capture element -

Answer 34

Remnant X-ray energy is captured. Indirect DR - amorphous Sillicon - converts X-ray to visible light

Question 35

Coupling element -

Answer 35

Transfers X-ray generated signal to collection element Indirect DR - amorphous silicon - light sent to photoconductive material

Question 36

Collection element -

Answer 36

Collects photons or electrons to be quantified - assigned a digital value

Question 37

Indirect DR -TFT -

Answer 37

electrons from photoconductive material collected by TFT

Question 38

Algorithm -

Answer 38

A finite sequence of instructions, an explicit step by step procedure for solving a problem, often used for calculation and data processing. A computers mathematical "recipe", not one size fits all

Question 39

Sampling -

Answer 39

The process used to digitize the spatial information in an image, typically achieved by dividing an image into a square or rectanglar array of sampling points.

Question 40

Spatial resolution -

Answer 40

The ability to see really small structures, the field of view, matrix size

Question 41

Pixel size -

Answer 41

Measured from side to side of the pixel, a less accurate measure, does not account for dead zones

Question 42

Pixel pitch -

Answer 42

Measures center of pixel to center of other; takes into consideration dead zones, a more accurate assessment.

Question 43

Pixel density -

Answer 43

``` the number of pixels per given area #/mm ```

Question 44

Cesium Iodide -

Answer 44

the scintillating phosphor material used in medical imaging specifically for the needle like crystals

Question 45

Why Cesium Iodide?? -

Answer 45

needle like crystals

Question 46

Amorphous -

Answer 46

having no shape or organization

Question 47

Indirect Conversion Flat Panel Detectors -

Answer 47

Detector that uses thin layers of amorphous silicon with an array of photodiodes - coated w/Photostimulable phosphor that emits light - converted to an electrical charge, signal sent to ADC to convert to digital signal.

Question 48

Amorphous Silicon - (a-Si) -

Answer 48

Phosphor material - emits light when stimulated

Question 49

Direct Conversion Flat Panel Detectors -

Answer 49

Uses a amorphous selenium coated TFT that directly converts X-ray to electrical signals. Absorbs remnant radiation in the selenium layers that are collected by capacitors, then sent to the ADC to convert to digital.

Question 50

Amorphous Selenium - (a-Se) -

Answer 50

Absorbs X-ray - converts directly to electrons (no light divergence)

Question 51

TFT - Thin Film Transistor -

Answer 51

Collect electric charges, positioned in a matrix, detects charges on a pixel by pixel basis. Capable of very high spatial resolution (greater than 20lp/mm)

Question 52

AMA - Active Matrix Array -

Answer 52

Amorphous silicon, capacitor, and TFT assembly

Question 53

DEL - Detector Element -

Answer 53

Small square capable of recording a certain number of electrons. The smallest possible dot of information.

Question 54

Capacitor -

Answer 54

Temporarily collects electrical signal

Question 55

Matrix -

Answer 55

The layout of cells in rows and columns containing pixels/voxels. The larger the matrix, the better the resolution.

Question 56

Hounsfeld Units/CT Numbers -

Answer 56

a quantitive scale for describing radio density calculated by comparing the linear attenuation coefficient of each pixel

Question 57

Dot/Matrix image -

Answer 57

A 2 dimensional patterned array, used to represent characters, symbols and images

Question 58

LP/mm - Line Pairs per Millimeter -

Answer 58

The measure of image sharpness. The ability of the human eye to see the number of high contrast pairs of lines appearing in the space of a single mm.

Question 59

Pixel -

Answer 59

the smallest component of a picture, 2 dimensional - length x width. Each pixel corresponds to a shade of gray.

Question 60

Voxel -

Answer 60

3 dimensional, volume element (CT scan) each voxel corresponds to a shade of gray representing a volume within a patient.

Question 61

Dynamic Range/Bit range/Bit Depth/Pixel Depth -

Answer 61

The range of gray shades that can be assigned to a pixel, the higher the range, the more gray shades available to display the image.

Question 62

Scintillation -

Answer 62

xray photons are converted to light within the flat panel detector by a layer of cesium iodide amorphous silicon

Question 63

The divergent properties of light -

Answer 63

Spreads out across all directions.

Question 64

The goal of ALL digital imaging systems is to convert x-ray energy into electron energy. Why?

Answer 64

Because electrons can be counted, either individually or as a sum negative charge. Counting something allows you to assign it a digital value. Computers can store information held as numbers (digital information held in a binary code), but they cannot store analog information.