Photon counting detectors are an emerging technology for spectral computed tomography. They have the potential to
improve tissue contrast and specificity, reduce dose, and enable novel applications for K-edge and functional imaging. In
this presentation various non-linear distortions were investigated that affect the image quality in photon-counting
spectral CT: deadtime losses and spectral response, inherent to the new technology, and beam hardening artifacts that
stem from the use of a polychromatic x-ray source. These effects were corrected or compensated for by performing
calibration measurements. Techniques from material decomposition were applied to reconstruct images at a desired
energy. Two methods were compared to synthesize a single monoenergetic image from photon counting data with
multiple energy bins. The parameters were optimized to maximize a given image quality index. The procedures were
evaluated on phantom data acquired on an experimental CT scanner with photon-counting detectors with two energy
thresholds.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J. Cammin ; S. Srivastava ; Q. Tang ; W. C. Barber ; J. S. Iwanczyk, et al.
"Compensation of nonlinear distortions in photon-counting spectral CT: deadtime loss, spectral response, and beam hardening effects", Proc. SPIE 8313, Medical Imaging 2012: Physics of Medical Imaging, 83131T (February 23, 2012); doi:10.1117/12.911217; http://dx.doi.org/10.1117/12.911217