Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
Caliper
|
a device used to measure the thickness of anatomic parts
|
|
|
Contrast
|
the measureable distance bt 2 adjacent densities
|
|
|
Density
|
degree of blackness on radiograph
|
|
|
Exposure time
|
period of time during which xrays are permitted to leave xray tube
|
|
|
Inverse Square Law
|
intensity of the radiation varies inversely as the square of distance from source decreases
|
|
|
Kilovoltage
|
related to thousands of volts of electrical potential bt cathode and anode
|
|
|
Kinetic energy
|
energy related to motion
|
|
|
mA's
|
number of xrays produced over given period
|
|
|
Milliampere
|
one thousandth of an ampere
|
|
|
Sante's Rule
|
a method of estimating kilovoltage in relation to area thickness
|
|
|
Thermionic emission
|
process of releasing electrons from their atomic orbits by heat
|
|
|
Backscatter
|
scattering or reflecting radiation in the opposite direction from that which was intended
|
|
|
crossed grid
|
2 parallel or 2 focsed grids that are set at right angles
|
|
|
elongation
|
distortion of anatomical structures so that image appears longer
|
|
|
focused grid
|
a grid with a parallel center lead strip and inclined strips on either side
|
|
|
foreshortening
|
distortion of anatomic structures when image appears shorter than actual size
|
|
|
geometric distortion
|
variation in normal size or shape
|
|
|
geometric unsharpness
|
loss of detail due to distortion
|
|
|
grid
|
deive made of lead strips embedded in spacing material placed bt patient and film, designed to absorb non-image forming radiation
|
|
|
grid cutoff
|
progressive decrease in transmitted xray
|
|
|
grid efficiency
|
ability of grid to absorb non-image forming radiation
|
|
|
grid factor
|
the amt of exposure needs to be increased to compensate for grids absorption
|
|
|
grid focus
|
the distance bt the source of an xray and the grid in which the grid is effective without grid cutoff
|
|
|
grid ratio
|
relation bt height of lead strips to the distance bt them
|
|
|
linear grid
|
grid in which lead strips are parallel
|
|
|
magnification
|
distortion of anatomic structures when inage appears larger then actual size
|
|
|
Potter-Bucky Diaphragm
|
moves grid across the xray
|
|
|
pseudofocused grid
|
grid with parallel lead strips that are progressively reduced in height toward the edge of the grid
|
|
|
radiographic contrast
|
density difference bt two adjacent areas
|
|
|
radiographic density
|
degree of blackness
|
|
|
radiographic detail
|
definition of edge of atomic structure
|
|
|
radiogrpahic quality
|
the ease in which details are perceived
|
|
|
scatter radiation
|
non0image forming radiation scattered in all directions
|
|
|
subject contrast
|
difference bt density and mass of two adjacent anatomic structures
|
|
|
unfocused grid
|
grid with leas strips that are parallel and are at right angles to film
|
|
|
detail and defintion - four things used to describe image
|
sharpness
clarity distinctness perceptability |
|
|
geometric unsharpness
|
atributed to
result of large focal spot or decreased SID motion sedation may be needed screens and films |
|
|
radiographic quality depends on these three things
|
radiogrpahic density
radiogrpahic contrast geometric factors that effect detail |
|
|
density is influenced by what four things?
|
quantity of beam
quality of beam type of tissue being radiographed thickness of tissue being radiographed |
|
|
greater radiogrpahic density may be produced by increasing
|
total # of xrays reaching film (mAs)
increased penetrating power of xrays (kVp) increased developing time temp of developer |
|
|
radiographic contrast is influenced by what 5 things?
|
subject contrast
kVp level scatter radiation film type used film fogging |
