CT Instrumentation

alkathryn's version from 2016-07-13 22:46


Question Answer
Three major systemsimaging, computer, communication/display/storage
Imaging system locatedin scanner room
Computer system locatedin computer room
Image display recording storage communication system locatedin operators room
Imaging system akaGantry
Imaging system dutiesproduce X-rays, shape and filter X-ray beams, detect and measure radiation passing through patient, convert transmitted photons to digital info
Imaging system componentsxray tube and generator, collimators, filter, detectors, DAS
DAS stands forData Acquisition System
Collimatorsdefine slice thickness and restrict the X-ray beam
Filterprotects the patient from low energy rays and ensures beam uniformity at the detectors
Detectorscapture the rays and convert them into electrical signals
ADC convertsanalog to digital
DAS containsamplifier, ADC, DAC, generator, S/H
Sample/hold unit locatedbetween amplifier and ADC
Sample/hold unit performssampling and assigns shades of gray to the pixels in the digital matrix corresponding to the structures