Quantitative radiographic imaging using a photostimulable phosphor system.
We have evaluated a photostimulable phosphor x-ray imaging system [Philips Computed Radiography (PCR) system] for use in quantification of x-ray exposure in diagnostic radiography. An exponential function was fitted to data yielding quantitative x-ray exposure values as a function of digital pixel values. We investigated several factors that affect the accuracy of exposure measurement using the PCR including repeatability, background noise as a function of time delay between plate erasure and use, sensitivity variation between different plates, nonuniformity of sensitivity within a plate, decay of the latent image between time of exposure and readout (observed as a change in sensitivity), and the accuracy with which the (exponential) calibration function yields exposure values as a function of digital pixel values. The calibration was performed over the exposure range from 5.1 X 10(-9) to 2.0 X 10(-5) C/kg (0.02-75 mR). The accuracy of exposure measurements made with a single imaging plate is between 1.6% and 4.2%. If measurements from several plates are involved, the uncertainty in the final measurement will be between 5% and 5.9%.
Floyd
C E
CE
Duke University Medical Center, Durham, North Carolina 27710.
Chotas
H G
HG
Dobbins
J T
JT
Ravin
C E
CE
D005069:Evaluation Studies as Topic; D006801:Humans; D008163:Luminescent Measurements; D011829:Radiation Dosage; D011859:Radiography / Q000295:instrumentation* / Q000592:standards