Advanced Imaging Mod 2

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_________________ is a style of image receptor for digital radiography (flat panel 14x17)

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113 Terms

1

_________________ is a style of image receptor for digital radiography (flat panel 14x17)

Active matrix array (AMA)

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2

_________________ is a device from video camera to computer

analog to digital converter (ADC)

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3

_________________ is when you tell the computer what view it is you're doing and it adjusts the image according to preset parameters (aka diagnostic specifier)

automatic data recognition

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4

_________________ is the slope of the tangent at any point on the characteristic curve

average gradient

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5

_________________ is the average density on unexposed areas of the film due to development of the AgBr crystals either through manufacturer defect or age plus the blue tint of the base

base/fog

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6

_________________ is an electron beam designed for 2 dimensional signal display

cathode ray tube (CRT)

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7

_________________ is a solid state device that converts visible light into a stored charge

charge-coupled device

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8

_________________ is a graph of optical density versus log relative response

characteristic curve (H and D curve)

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9

_________________ is the degree of difference between the light and dark areas of a radiograph

contrast

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10

_________________ uses photostimulable phosphor as the image receptor and a computer

computed radiography

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11

_________________ converts light into electronic signal

Complementary Metal Oxide Semiconductor (CMOS)

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12

_________________ is the area on a characteristic curve of least density

D min

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13

_________________ is the area on a characteristic curve of highest possible density

D max

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14

_________________ is an instrument that measures the optical density of exposed film

densitometer

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15

_________________ is an area x-ray beam intercepted by phosphor plate or CCD into digital

digital radiography

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16

_________________ is DR that uses selenium as image receptor

direct-capture radiography

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17

_________________ is range of values that can be displayed by an imaging system (gray shades), number of gray shades that can be represented.

-also is written in bit depth

dynamic range

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18

_________________ is the ability to use a wide range of of exposure factors and produce a quality image

exposure latitude

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19

_________________ is the straight line portion of the characteristic curve

film gradient

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20

_________________ is the film's ability to produce a wide range of values or gray scale

film latitude

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21

_________________ is the density produced on a film due to unintended development of the AgBr crystals in the film - may be due to exposure to light or x-rays, age, chemical

fog density

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22

_________________ is the name a computer gives to an x,y graph

Histogram

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23

_________________ is a layout of cells (pixels) in rows and columns. Size of this affects spatial resolution.

-multiply column by rows to find this.

Larger the ___ __the _______ the detail

image matrix, matrix, detail

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24

_________________ is the fact that film is 5 times more sensitive to another exposure after the initial exposure from x-rays

latensification

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25

_________________ is a type of display system for computer monitors/calculators

liquid crystal displays (LCD)

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26

_________________ is a description for something that is straight

linear

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27

_________________ is a process in computerized imaging where the computer processes an image further to mimic the traits desired for a specific view

normalization/automatic rescaling

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28

_________________ - Io/It = light originally hitting film/light transmitted through film

-measures optical density

density

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29

_________________ is the degree of blackening of a radiograph

optical density

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30

_________________ is an aluminum step wedge

penetrometer

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31

_________________ is material that gives off light after x-ray and/or laser stimulation

photostimulable phosphor

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32

_________________ is the study of the response of an image receptor to x-rays/light

sensitometry

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33

_________________ is an optical step wedge that is used to construct a characteristic curve

sensitometer

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34

_________________ is an imaging system's ability to respond to a minimum quantity of x-rays

speed

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35

_________________ is the process where any exposures after maximum film density will actually decrease density due to remigration of the silver away from the sensitivity center

solarization

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36

_________________ is the amount of background electrical noise that obscures the electric signal

signal to noise ratio (SNR)

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37

_________________ is the ability to image small objects that have high subject contrast, computer term for detail

spatial resolution

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38

_________________ is a type of image receptor for digital radiography

thin film transistor (TFT)

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39

_________________ is the location on a digital image number scale where grays are assigned, controls the brightness on a monitor

window level

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40

_________________ is a number of gray levels or digital image number scale determines image contrast

window width

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41

What photographers in 1890 in England created the characteristic or sensitometric curve? (happened before or after the discovery of x-rays?

F. Hurter and VC. Driffield (also called H and D curve), before

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42

_________________ is used as a guideline to correct images by computers

H and D curve

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43

T or F - photographic characteristics of x-ray film and camera film are the same

True

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44

_________________ is a graphic representation of density/blackness

sensitometry

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45

x-axis of H and D curve contains the _________________ while the y-axis shows the _________________

log relative exposures, shade gradient

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46

H and D curve -

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47

H and D curve - x-axis is a scale from _______ to _________ and goes up in increments of . It is labeled _____________.

0-3, .3, log relative exposure

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48

y-axis is a scale from _______ to _______ and it is labeled _________________ with _______ on bottom and ______ on top

0-4, shade gradients, white, black

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49

_________________ on the H and D curve is right before it curves. _________________ is between the toe and shoulder (most useful part because it contains the shades of grey), _________________ is where it plateaus and where D max is located

toe, slope/gradient, shoulder

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50

_________________ is the minimum density possible and why doesn't it start at 0?

D min and because film already being tinted, manufacturing causing silver to blacken, and us needing to process film causing the raising of D min.

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51

_________________ is maximum density possible.

D max

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52

More _________________ means higher D max. If you have a D max higher or lower than normal, it is a _________________ issue.

silver, silver

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53

D min can be lower due to having less ___________. (single emulsion D min is ____________ than double emulsions D min)`

silver, lower

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54

anytime the processor is too strong, D min goes ____________ due to exposing unexposed crystals

up

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55

____________ and ____________ are devices that imparts a gray scale onto film

aluminum step wedge (penetrometer), sensitometer

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56

____________ are steps of Al that are different types of thicknesses that creates a gradient. Need to x-ray it

aluminum step wedge/penetrometer

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57

____________ has a gradient and uses light instead of x-rays to mimic increasing exposure levels

sensitometer

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58

____________ is used to measure the shade the aluminum step wedge/penetrometer and sensitometer created. It measures optical density using ___________ formula.

densitometer, D=log Io/It

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59

D=log Io/It

___________ = light originally hitting film, ___________ = light transmitted through film

Io, It

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60

With the optical density formula, if a lot of light gets through, it means a ___________ number, if little light gets through, it means a ___________ number

smaller, bigger

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61

Why is density expressed as a logarithm?

to express large numbers and make the large number easier to manipulate/handle

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62

When checking base and fog density, what should the measurement be? base is ___________ and fog is ___________

less than .25, blue, extra exposure

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63

if the slope/gradient in an H and D curve is steeper it means ___________ contrast, so a more shallow slope means ___________ contrast, and the closer the slope/gradient is to the y-axis means ___________ sensitivity/speed, so if the slope is farther away from the y-axis it means ___________ speed/sensitivity

more, less, more, less

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64

In x-ray, gradient is always greater than ___________ (45 degree slope = ___________)

1, 1

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65

useful range of density readings are ___________ to ___________ (Dmin to Dmax)

.25-2.5

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66

___________ is how many different gray values a film will have per exposure

film lattitude

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67

___________ latitude is shallow slope which means more exposure values are available to use to get good film

wide

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68

film latitude is ___________ related to contrast which means the steeper the slope, the less latitude a system has.

inversely

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69

___________ = closeness to y-axis

___________ = steepness of slope (more steep means more)

___________ = steepness of slope (shallower slope means more)

speed, contrast, film latitude

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70

When the curve changes on an H and D curve, it means what?

that something happened to the film (like a higher base means film was already darkened)

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71

__________ is the film's ability to respond to a minimum amount of exposure

speed/sensitivity

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72

so a 100 speed image receptor will have a slope ___________ y-axis and a 400 speed image receptor will have a slope ___________ y-axis

farther from, closer to

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73

___________ is related to AgBr size and emulsion thickness

speed/sensitivity

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74

curve uses in the past (only on film)

___________ ___________ ___________ is when using a step wedge, make initial curve, and look for changes over time

___________ ___________ ___________ is when using a test strip to check how the chemistry is in the processor (H and D curve will be affected if chemistry is bad)

evaluate tube output, evaluate processor chemistry

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75

Changes in slope or speed indicate ___________ is getting old or contaminated when evaluating processor chemistry

chemistry

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76

_________________ was a way to analyze if film was working properly by looking at its graphic representation

sensitometry

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77

___________ is used in computerized radiography and ___________ or ___________ is used in digital radiography. These receive remnant and scatter radiation from the patient the same as ___________

europium activated barium fluorohalide (Eu: BaFBr/I), cesium Iodide (CsI) or amorphous selenium (a-Se), film

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78

How does the computer know when the exposure is right in Computerized and Digital radiography? It uses ___________ and ___________ ___________

histograms, automatic rescaling/normalization

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79

___________ is a bar graph showing how many pixels of each shade are present.

histograms

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80

histograms require you to run the x-ray under the right _/_ because histograms differ with different _/_, so the computer will use the right histogram to fix the image.

part type/view, part type/view

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81

_/_ ___________ is when the computer sorts pixels by shade. There are numerical values for each pixel's shade of black-grey-white and there are ___________ different shades a pixel can be

pixel/image sampling, 4096

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82

The computer also fixes radiographs by using ___________ ___________ of perfect radiographs as a reference

H and D curves

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83

___________ _/_ is applying histograms of perfect x-rays to an x-ray to fix an image. Also can be defined as the computer adjusting the bars in an histogram to "fix" or adjust the histogram from the x-ray you took to make the radiograph better

automatic rescaling/normalization

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84

___________ ___________ is a file the computer has of all the perfect histograms of films (computer can't understand pictures - only pixels), so it uses histograms

look-up table (LUT)

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85

___________ and ___________ are digital imaging quality indicators

s-value, exposure index EI_s

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86

for s-value higher number = ___________ exposure, a good average is _. For EI_s higher numbers = _ exposure, a good average is ___________.

lower, 200, higher, 300-400

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87

When L-value goes up = latitude goes _______

Low kV = ___ L-value

up, higher

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88

What is the issue with image manipulation?

our image manipulation limits what the Rads can manipulate. We could take out pathology. Some windowing the Rad can't undo.

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89

___________ is changing contrast and brightness after the image is taken

windowing

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90

Review of CR

plate exposed to remnant x-ray photons ionization of bromine or iodine (___________% Bromine)

___________ colored light is given off as ___________ of the Bromine atoms get their shells filled. The other half, stays empty, held onto by Europium, and will eventually be filled in ___________ hours. Images are readable up to ___________ hours

90%, purple, half, 16, 8

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91

Scanning of the plate with a laser (CR)

___________ is when the laser is a line, it is quicker -less than 10sec, captures more info

___________ is when the laser is the size of a laser pointer, slower - 30+ secs, and misses some info (outdated)

line scan, point scan

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92

___________ is a red LED (light emitting diode) or HeN (helium neon) laser scans the plate at a predetermined sampling frequency (2-7 sec). (LASER IS JUST MOVING). If it moves too fast = ___________ data. ___________ is considered this

fast scan, less, line scan

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93

/ ___________ is if a laser is going too fast, it samples less info, if a laser is moving slower, it means sampling more info.

-extremities scan ____ for more info

scanning/sampling frequency, slower

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94

___________ is the mechanical movement of the screen as the laser is also moving across it (LASER AND SCREEN IS MOVING AT SAME TIME)

slow scan

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95

___________ is caused when there are areas of less and more densities causing artifact due to slow moving mechanism of screen and fast moving laser not being synced or coordinated properly.

-flat fielding fixes this

banding artifact

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96

After the scanning of laser, the other half of electrons are put back into bromine/iodine which results in ___________ light given off again

violet

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97

Filters remove red laser light. The remaining violet light after the scanning of the laser contains image information and is detected by a ___________ _/____________

photomultiplier tube/photocathode

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98

___________ ___________ detects light and send electronic signal in response, based on how much light is received. (more exposure = ___________ light)

photomultiplier tube/photocathode, more

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99

___________ ___________ is electronic calibration that fixes pre-processing stuff, will fix banding artifact

flat fielding

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100

There is ___________ based DR and ___________ based DR

indirect capture/scintillation, direct capture

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