Radiographic Terms Flashcards
AUTOMATIC COLLIMATION
(PBL)- positive beam limitation
- constricts beam
- when using cassette, sensors sense size of cassette and collocates down
ANODE
“Target”
- positive electrode
- receives electrons
BLUR
“Image blur” “penumbra”
- unsharpness
- checking trabecular pattern
BUCKY
Device that holds cassette in table
CASSETTE
Film screen- silver bromide crystals->black metallic silver
-rare earth phosphors light up
CR- imaging plate
-barium fluoro halide
CATHODE
“Filament”
Negative electrode
-lights up to incandescence
-forms space charge called “cloud of electrons”
CONTRAST
Differences in density
Short scale (high contrast)-whites/blacks , no grays.
Long scale (low contrast)-
More grays, whites/blacks
DENSITY
Overall blackening of image
DISTORTION
Misrepresentation of image
-size or shape
IMAGE RECEPTOR
Anything that receives image
- image intensifier
- film screen cassette
- I.p.- imaging plate
FOCAL SPOT
Where electrons hit anode
-small focal spot- sharper image
Steeper angle= smaller degree= focal spot
GRID
Absorbs scatter
- image quality device
- not a radiation protection device
- need more radiation because has to go through lead plate
INTENSIFYING SCREEN
Light up during exposure
- rare earth phosphors
- 95% light 5% X-ray
KVP
Quality
-beam penetration controls contrast
LEAD APRONS
Secondary barrier
-used during fluoro
MAS
Quantity
- # of photons
- controls density
OID
“OFD”
Object-image distance
-low oid= increased sharpness
AUTOMATIC PROCESSOR
4 tanks-
- developer-changes latent image to manifest
- fixer-hardens emulsion, gets rid of unexposed silver bromide crystals
- wash- washes off excess chemicals
- dry
LASER PRINTER
Makes Hard copies of xrays from digital
RADIOGRAPH
X-ray image after exposed and processed - legal record used in court cases Ensure: 1. Image quality 2. Verify identity 3. Left/right markers are correct
RADIOGRAPHIC POSITION
Specific position of body or part in relation to table or image receptor
RADIOGRAPHIC VIEW
Image
-how body part is seen on on X-ray view
RECORDED DETAIL
Sharpness- definition/resolution
-how clear the boundary of image is.
SID
(FFD) -source image distance
-anode to image receptor
SOD
FOD
- source to object distance
- between anode to patient
CR
-computed radiography
-using cassette with imaging plate-barium fluoro halide phosphors.
Put in image reader, laser scans image.
CRT
Cathode Ray tube-
Monitor that brings up image
DICOM
Digital Imaging Communicating Medicine
-Software used for blending modalities
DR
Digital radiography
-uses detectors
-selenium/silicon
Silicon uses scintillator
HIS
Hospital info system
HISTOGRAM
Graphic display of distribution of pixels
PACS
Picture archiving communication system
- network to transfer images
PIXEL
Boxes of data
-smallest component of matrix
REMNANT BEAM
(Exit radiation)-leftover radiation
- X-ray beam that exits patient
- made up of image forming rays that hit I.R. (Image reader)
RIS
Radiology info system
-use for EDE
VOXEL
3-dimensional pixel
-volume element
-used in CT/MRI/3d ultrasound
-
WINDOW LEVEL
Adjusting density (post parameters) -after image is in comp
WINDOW WIDTH
Adjusting contrast-after image is on comp
MAGNIFICATION
SID-FFD
OID-OFD
SOD-FOD
-more KV =less magnification
