Photon counting and energy discriminating detector threshold calibration

摘要

An imaging system includes an x-ray source, a detector that receives x-rays emitted from the x-ray source, a DAS configured to count photon hits in the detector that occur at photon energies above at least a low keV threshold, a medium keV threshold, and a high keV threshold, and a computer operably coupled to the DAS. The computer is programmed to vary each of the medium keV threshold and the high keV threshold over a continuous keV range during data acquisition to define low, medium, and high keV bins that are based on the low, medium, and high keV thresholds, obtain photon counts in the low, medium, and high keV bins in a plurality of keV threshold combinations, calculate a noise variance as a function of at least one of the keV thresholds, and identify a noise minimum and low, medium, and high keV thresholds that correspond thereto.