COMPUTED & DIGITAL RADIOGRAPHY Flashcards
What is the formula for measurement of kVp?
kVp= body thickness x2 + constant
it is a digital acquisition process that produces images that have much better contrast than a conventional x-ray film system
Computed Radiography (CR)
a process of capturing radiographic data from a conventional x-ray machine and processing the data digitally to produce crisp and high quality radiographic images
Computed Radiography (CR)
it is placed in a cassette instead of a piece of film
Imaging Plate (IP)
responsible for capturing and storing x-ray
Imaging Plate (IP)
it is where the image is developed instead of a film processor; and extracts information stored in the plate and produce a digital image
CR reader
what material does an imaging plate made of
photostimulable phosphor
has a special property of storing the x-ray energy in a latent form and releasing the same when stimulated by laser energy in the CR reader / digitizer
photostimulable phosphor
is a material analogous to an inorganic scintillator, with the difference that in a storage phosphor, a significant part of the energy released on interaction with radiation is stored in long-living traps.
storage phosphor
what kind of material is phosphor
bariumflourohalide
give the layers of an imaging plate
- phosphor layer
- protective coat
- conductive layer
- support and laminate layers
an image exposed but not developed
latent image
created image in a form of energy
latent image
what does the beam releases after the stimulation with a laser
electrons
what is the typical wavelength of the stimulating laser
633nm
electrons emit luminescent light
falling back
typical wavelength for the emitted light
390nm
Stimulable Phosphor Receptor Reading Phase
scanning laser –> analog/digital converter –> digital image –> computer memory
is emitted light intensity proportional to the original incident x-ray intensity? yes or no
yes
it is erased from the plate by an intense light source which returns electrons to their original state
residual image
what is the common size for a cassette?
14 x 17 nm
TRUE OR FALSE: storage phosphor plate fits inside a standardized size cassette and is exposed to x-ray exactly like film
true
where the patient demographic and exam data is store on the microchip attached to the cassette
patient ID station
it is where the plate is inserted and scanned with high power laser, where electrical signals are converted into digital image
digitizer
it travels to the speed of light
x-rays
it is responsible for amplifying the energies/ light; and it is converted into photo diode to electrical signals
photomultiplier
what happens to storage phosphor after it is scanned?
phosphor plate is erased by exposing to a bright light within the digitizer
where the digitized image is processed on a processing server and its displayed on its monitor
work station
how many times can we use Storage Phosphor Plate (SPP)?
depends on how carefully it is handled
how many exposure cycles does the imaging plate has
5,000 exposurere cycles
TRUE OR FALSE: one CR can support multiple x-ray rooms
true
what is the last product in CR
film
what is the first product in conventional x-ray
film
TRUE OR FALSE: CR can be developed without digitizer
false, must have digitizer
illustrate the CR workflow
cassette w/ IP -> Exposure -> Identification (patient data) ->Digitize -> printing processing server -> storage
