Method of monitoring changes in the detective quantum efficiency of an x-ray detector
AssigneeGE Medical Systems Global Technology Company, LLC
InventorsRichard Aufrichtig, Paul R. Granfors
Life of this patent
Estimating the term…
Abstract
Automated measurement of changes in detective quantum efficiency (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.
Claims20
A process for determining changes in the detective quantum efficiency (DQE) of an x-ray detector in an x-ray system comprising:
- determining the modulation transfer function (MTF) of the x-ray detector using an image quality phantom;
- determining the noise power spectrum (NPS) of the x-ray detector using flat field images;
- calculating a normalized noise power spectrum (NNPS);
- computing the ratio of (MTF)2/NNPS;
- and
- monitoring said ratio as a function of time.
Dependencies are inferred from the claim text.