Method for the Correction of Spectral Distortions in X-Ray Photon-Counting Detectors

Energy-resolved photon-counting detectors (PCD) present the ability to enhance material identification in different X-ray radiography and tomography systems employed for industrial and security applications. Their potential has been proven to be higher than the dual-energy scintillator detectors broadly used nowadays. However, detector effects, like photon pileup and charge sharing, distort the energy spectrum in PCDs. These effects lead to a significant performance deterioration of the PCDs when used for material identification where accurate measurements of multienergy linear attenuation coefficients (LACs) are needed. We have proposed a method that rapidly corrects the measured raw LAC curve for significant spectral distortions in the image reconstruction domain. This method is based on polynomial fitting independently for each energy channel. The method has been validated with experimental data, and the calibration of the method is based on attenuation measurements of common materials with usual laboratory X-ray sources, allowing the method to be employed in any X-ray instrument. The experiments present that the method largely enhances the extraction accuracy of the multienergy LACs, making it helpful for industrial, medical, and security purposes where PCDs are used.