221 Final review Flashcards
With digital imaging, patient dose can be reduced by using higher___.
kVp
In digital imaging, spacial resolution is ultimately limited by ____.
pixel size
Overexposure in digital radiography results in ___.
plate saturation and decreases contrast
A different x-ray unit must be bought to take digital x-rays
T/F
False
This type of digital radiography requires a cassette and processor.
Computed Radiography
What is the cause of most retakes in digital radiography?
Poor positioning
T/F - kVp does not control contrast on a digital image?
True
In digital imaging, brightness is called…?
Window Level
What is noise in digital imaging?
exposure and scatter
Backscatter on a digital image can cause an artifact called___
Phantom image artifact
When are film intensifying screens used?
Conventional
Intensifying screens do what?
emit light when struck by x-rays
CR aquires a image through the use of
storage phosphor plates
In the DR system, what is need to produce the radiographic image?
CCD, x-ray absorber
What is the x-ray absorber in DR?
photoconductor
It takes ___ seconds to aquire the image in conventional and only ___ seconds in DR.
90 and 3-5
What is active element in storage phosphor plate?
Barium Fluorohalide
What is scanned over the phosphor plate to release the image?
focus laser light
Sequence for PSP image capture?
Phosphor plates, focus laser light scanner, photomultiplier, analog digital converter, review station
The two elements needed to convert light signals into an electrical signal while using indirect capture DR are TFT and
photodiodes
X-ray energy related to direct capture Dr will stimulate a _______ which eventually is changed into an electrical signal
Scintillator
What does a photoconductor do?
converts energy into a digital electric signal
Exposure latitude in conventional rad is equivalent to what in DR?
Dynamic range
Optical density is primarily controlled by ___ in CR.
mAs
