Advanced Imaging Mod 2

studied byStudied by 5 People
5.0(1)
Get a hint
hint

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

1/113

Studying Progress

New cards
113
Still learning
0
Almost done
0
Mastered
0
113 Terms
New cards

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

Active matrix array (AMA)

New cards
New cards

_________________ is a device from video camera to computer

analog to digital converter (ADC)

New cards
New cards

_________________ 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

New cards
New cards

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

average gradient

New cards
New cards

_________________ 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

New cards
New cards

_________________ is an electron beam designed for 2 dimensional signal display

cathode ray tube (CRT)

New cards
New cards

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

charge-coupled device

New cards
New cards

_________________ is a graph of optical density versus log relative response

characteristic curve (H and D curve)

New cards
New cards

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

contrast

New cards
New cards

_________________ uses photostimulable phosphor as the image receptor and a computer

computed radiography

New cards
New cards

_________________ converts light into electronic signal

Complementary Metal Oxide Semiconductor (CMOS)

New cards
New cards

_________________ is the area on a characteristic curve of least density

D min

New cards
New cards

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

D max

New cards
New cards

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

densitometer

New cards
New cards

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

digital radiography

New cards
New cards

_________________ is DR that uses selenium as image receptor

direct-capture radiography

New cards
New cards

_________________ 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

New cards
New cards

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

exposure latitude

New cards
New cards

_________________ is the straight line portion of the characteristic curve

film gradient

New cards
New cards

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

film latitude

New cards
New cards

_________________ 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

New cards
New cards

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

Histogram

New cards
New cards

_________________ 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

New cards
New cards

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

latensification

New cards
New cards

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

liquid crystal displays (LCD)

New cards
New cards

_________________ is a description for something that is straight

linear

New cards
New cards

_________________ 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

New cards
New cards

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

-measures optical density

density

New cards
New cards

_________________ is the degree of blackening of a radiograph

optical density

New cards
New cards

_________________ is an aluminum step wedge

penetrometer

New cards
New cards

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

photostimulable phosphor

New cards
New cards

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

sensitometry

New cards
New cards

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

sensitometer

New cards
New cards

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

speed

New cards
New cards

_________________ 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

New cards
New cards

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

signal to noise ratio (SNR)

New cards
New cards

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

spatial resolution

New cards
New cards

_________________ is a type of image receptor for digital radiography

thin film transistor (TFT)

New cards
New cards

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

window level

New cards
New cards

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

window width

New cards
New cards

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

New cards
New cards

_________________ is used as a guideline to correct images by computers

H and D curve

New cards
New cards

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

True

New cards
New cards

_________________ is a graphic representation of density/blackness

sensitometry

New cards
New cards

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

log relative exposures, shade gradient

New cards
New cards

H and D curve -

New cards
New cards

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

New cards
New cards

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

0-4, shade gradients, white, black

New cards
New cards

_________________ 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

New cards
New cards

_________________ 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.

New cards
New cards

_________________ is maximum density possible.

D max

New cards
New cards

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

silver, silver

New cards
New cards

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

silver, lower

New cards
New cards

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

up

New cards
New cards

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

aluminum step wedge (penetrometer), sensitometer

New cards
New cards

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

aluminum step wedge/penetrometer

New cards
New cards

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

sensitometer

New cards
New cards

____________ 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

New cards
New cards

D=log Io/It

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

Io, It

New cards
New cards

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

New cards
New cards

Why is density expressed as a logarithm?

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

New cards
New cards

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

less than .25, blue, extra exposure

New cards
New cards

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

New cards
New cards

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

1, 1

New cards
New cards

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

.25-2.5

New cards
New cards

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

film lattitude

New cards
New cards

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

wide

New cards
New cards

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

inversely

New cards
New cards

___________ = closeness to y-axis

___________ = steepness of slope (more steep means more)

___________ = steepness of slope (shallower slope means more)

speed, contrast, film latitude

New cards
New cards

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)

New cards
New cards

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

speed/sensitivity

New cards
New cards

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

New cards
New cards

___________ is related to AgBr size and emulsion thickness

speed/sensitivity

New cards
New cards

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

New cards
New cards

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

chemistry

New cards
New cards

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

sensitometry

New cards
New cards

___________ 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

New cards
New cards

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

histograms, automatic rescaling/normalization

New cards
New cards

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

histograms

New cards
New cards

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

New cards
New cards

_/_ ___________ 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

New cards
New cards

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

H and D curves

New cards
New cards

___________ _/_ 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

New cards
New cards

___________ ___________ 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)

New cards