publications by James T. Dobbins.
Papers Published
- Floyd, CE; Chotas, HG; Dobbins, JT; Ravin, CE, Quantitative radiographic imaging using a photostimulable phosphor system.,
Medical Physics, vol. 17 no. 3
(1990),
pp. 454-459 [2385203], [doi] .
(last updated on 2023/06/01)Abstract:
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%.Keywords:
Evaluation Studies as Topic • Humans • Luminescent Measurements • Radiation Dosage* • Radiography • instrumentation* • standards