Image Production And Evaluation Flash Cards

Front 1

Density

Back 1

The amount of blackness on a given area of a radiographic image, either film-screen or digital

Front 2

kVp

Back 2

Controls the energy of x-rays produced, also has a direct impact on density, although not proportional; governed by the 15% rule

Front 3

Source-to-image distance

Back 3

Distance from the x-ray tube anode to the image receptor, affects density through the inverse square law; controls magnification and image blur; the longer the SID, the better the recorded detail

Front 4

Film-screen combination

Back 4

In analog imaging, the speed of the film-screen combination has a direct effect on density

Front 5

Grids

Back 5

Absorb scatter radiation; this has an impact on the density and contrast of the image

Front 6

Beam restriction

Back 6

Limits the size of the area of the x-ray beam; affects density and contrast by reducing the amount of scatter produced

Front 7

Anode heel effect

Back 7

Has some effect on density when a large field is exposed

Front 8

Contrast

Back 8

Differences in adjacent densities on the radiographic image

Front 9

High Contrast

Back 9

Few gray tones, mainly black and white image; may also be referred to as short-scale contrast; produced at lower kVp

Front 10

Low contrast

Back 10

Many gray tones on image; may also be referred to as long-scale contrast; produced at higher kVp

Front 11

Subject Contrast

Back 11

Controlled by anatomy and pathology; affects contrast through variations of atomic number, tissue thickness, and tissue density

Front 12

Object-to-Image Distance

Back 12

The distance from the object to the image receptor; controls magnification of the image and image blur, the shorter the OID, the better the recorded detail

Front 13

Focal Spot Size

Back 13

Controls image blur; use small focal spot whenever possible to keep x-rays coming off the anode from the smallest possible area

Front 14

Distortion

Back 14

Any misrepresentation of an anatomic structure on an image receptor that alters its size or shape

Front 15

Size Distortion

Back 15

Magnification; caused by excessive object-to-image distance or insufficient source-to-image distance

Front 16

Shape Distortion

Back 16

Elongation or foreshortening

Front 17

Elongation

Back 17

Causes anatomic structure to appear longer than in reality; caused by improper tube, part, or film angulation or alignment, with angulation along the long axis of the part

Front 18

Foreshortening

Back 18

Causes anatomic structure to appear shorter than in reality; caused by improper tube, part, or film angulation or alignment, with angulation along the long axis of the part

Front 19

Film

Back 19

Composed of base and emulsion

Front 20

Base

Back 20

Made of plastic; holds emulsion; provides stiffness for handling; contains blue dye to reduce glare and enhance contrast

Front 21

Emulsion

Back 21

Contains silver halide crystals suspended in gelatin that will be exposed by intensifying screen light and x-rays

Front 22

Sensitometry

Back 22

Use of H & D curves to graphically demonstrate a film’s speed and contrast

Front 23

Toe

Back 23

Portion of the H & D curve representing base plus fog; 0 to 0.25 density

Front 24

Body

Back 24

Portion of the H & D curve representing the usable densities; 0.25 to 0.5 density; slope of the body indicates overall gray scale

Front 25

Shoulder

Back 25

Portion of the H & D curve representing maximum density; 2.5 to D-max

Front 26

Reflective Layer

Back 26

Between base and active layer of the intensifying screen; reflects light from phosphors toward film, increasing the speed of the system

Front 27

Protective Layer

Back 27

Thin coating placed on top of active layer of the intensifying screen to provide protection from scratching or other damage

Front 28

Screen Speed (sensitivity)

Back 28

Controlled primarily by phosphor used, phosphor size, active layer thickness, efficiency of reflective layer

Front 29

Conversion Efficiency

Back 29

How efficiently intensifying screen phosphors absorb x-ray energy and convert it to visible light

Front 30

Spectral Matching

Back 30

Wavelengths to which film is most sensitive must be matched with wavelength of light emitted by intensifying screens

Front 31

Grid Frequency

Back 31

Number of lead strips per inch (or centimeter)

Front 32

Linear Grids

Back 32

Lead strips are parallel to one another

Front 33

Focused grids

Back 33

Lead strips are angled to coincide with divergence of the x-ray beam

Front 34

Grid conversion factor

Back 34

Also called Bucky factor; amount of mAs exposure increase necessary to compensate for the absorption of image-forming rays and scatter in the cleanup process

Front 35

Upside-down grid

Back 35

Result will be normal density in the middle of the radiograph with decreased density on the sides

Front 36

Off-level Grid

Back 36

Result will be image-forming rays absorbed all across the radiographic field, with cutoff (decreased density) visible over the entire radiograph

Front 37

Developer

Back 37

Converts exposed silver bromide crystals (latent image) to black metallic silver (visible image)

Front 38

Fixer (hypo)

Back 38

Clears and removes unexposed silver bromide crystals

Front 39

Washing solution (water)

Back 39

Removes chemicals remaining on film

Front 40

Dryer

Back 40

Dries film after it leaves wash tank; approximately 120 degrees F

Front 41

Transport System

Back 41

Moves film through the processor; agitates chemistry

Front 42

Entrance Roller

Back 42

Grabs film and activates replenishment pumps

Front 43

Replenishment System

Back 43

Adds fresh developer and fixer solution for each film fed into the processor; this occurs as film is being fed into processor; activated by microswitch at end of entrance roller

Front 44

Recirculation System

Back 44

Agitates developer solution to prevent stratification of chemicals; helps stabilize developer temperature; removes reaction particles by use of a filtration system