What are the 4 ways to convert invisible ionizing radiation into a visible image?RXCN
radiography
xerorediography
computed tomography
nuclear scintigraphy
What uses gamma radiation to scan bone and locate metabolic activity/new growth to pinpoint injury?
nuclear scintigraphy
Formed with light-sensitive film contained in a cassette.
radiograph
Holds double-emulsion x-ray film between intensifying screens.
cassette
Convert x-ray radiation into visible light, thereby creating a latent image on the film.
intensifying screens
Converted to a visible image via processing
latent image
Film holder that holds the x-ray film and intensifying screens in close contact.
cassette
The cassette is _ tight
light
front of cassette =
plastic
back of cassette=
lead to prevent backscatter
How many quadrants may a cassette have?
quad=4 duh
Name the 3 most common cassette sizes
8x10
11x14
14x17
Why there a 3x7 cm section of lead on the cassette?
keep film from being exposed
Film is ID'd where?
dark room
Decrease the amount of radiation exposure required to produce a diagnostic radiograph
intensifying screens
Efficiency of the screen depends on what 3 factors?
high level of x-ray absorption
high x-ray to light conversion
little to no afterglow
What do the intensifying screens have layers of?
luminescent phosphor crystals that floresce when struck by x-rays
95% of film exposure
light
5% of film exposure
x-rays
4 layers of intensifying screens:BRPP
base
reflective
phosphor
protective
Attaches phosphor layer to cassette
base layer
reflects light emmitted by phosphor layer back towards the x-ray film
reflective layer
Made of calcium tungstate or rare earth crystals.
Absorbs x-rays
Emits light
Stops emmitting light immediately after exposure
Phosphor layer
calcium tungstate crystal
emits blue light
rare earth crystal
emits green light
better than calcium tungstate
Clear coating on outer surface of screenprotects phosphor layerresists marks and abrasionseasy to clean
protective layer
What can alter exposure
any foreign material b/t the screen and film
Intensifying screen speed depends on:CPRD
crystal size
phosphor layer thickness
reflective layer efficiency
dyes in phosphor layer to decrease blurring
Quantum mottle
speed artifact due to inc in speed which causes variation in density on flm
thicker phosphor layer=
more blurry image
Slow screen sped AKA: HUF
high definition
ultra detail
fine grain
Slow screen =
_ crystals
_ detail
_ mAs
small
high
high
Medium screen speed AKA:RMNP
regular
midspeed
normal
par speed
Most common screen speed used?
medium
Medium speed+ _ resolution
good
Fast screen speed=
_exposure time
_mAs
_crystals
_ detail
dec
low
large
less
Fast screens can penetrate _ tissues
thicker
X-ray film has a _ base on both sides with a light sensitive emulsion that contains _ _ crystals.
polyester
silver halide crystals
Processing film does what?
convert the split silver halide crystals to a visable image
What are the 4 layers of the x-ray film? BAEP
base
adhesive
emulsion
protective
covering
Silver crystals are sensitive to flourescent light emitted by the intensifying screens, but less sensitive to _. This helps them require less radiation.
ionizing radiation
Exposure range over wchich acceptable densities are produced.
film latitude
Forgiving film. Accepts variations in exposure factors or processing without a major change to density.
wide latitude
High contrast film. Requires less change in exposure factors or processing to affect density.
Narrow latitude
Large crystals
Granier image that lacks definition
fast film speed
Most widely used in vet med
Compromise between gran and speed
medium film speed
Small crystals
Less grainy image
Greater definition
slow film speed
Combined speed of screen and film determines the _ needed.
exposure
What differs with manufactuers?
film number
Medium speed #
300-400
As the speed of the system increases the _ decreases
mAs
Non-screen film sensitive to _
direct x-rays
Non-screen films need greater exposure factors because there is no _ of beam from light.