A METHOD OF MONITORING CHANGES IN THE DETECTIVE QUANTUM EFFICIENCY OF AN X-RAY DETECTOR

摘要

Automated measurement of changes in detective quantum efficieny (DQE) within an x-ray detector. The calculation of relative DQE changes is limited to the measurement of two quantities, namely MTF(f) and NPS(f). The measurement of MTF is obtained using an image quality phantom technique. The measurement of NPS includes the use of a flat field phantom, and data can be obtained during system calibration. Detector degradation and potential field replacement, are determined by monitoring the ratio of DQE as a function of time.