Compensation of nonlinear distortions in photon-counting spectral CT: Deadtime loss, spectral response, and beam hardening effects

J. Cammin, S. Srivastava, Q. Tang, W. C. Barber, J. S. Iwanczyk, N. E. Hartsough, K. Taguchi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


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.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2012
Subtitle of host publicationPhysics of Medical Imaging
StatePublished - 2012
EventMedical Imaging 2012: Physics of Medical Imaging - San Diego, CA, United States
Duration: Feb 5 2012Feb 8 2012

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherMedical Imaging 2012: Physics of Medical Imaging
Country/TerritoryUnited States
CitySan Diego, CA


  • beam hardening
  • deadtime losses
  • energy-resolved computed tomography
  • material decomposition
  • photon-counting detectors
  • pulse-pileup
  • spectral CT
  • spectral response

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging


Dive into the research topics of 'Compensation of nonlinear distortions in photon-counting spectral CT: Deadtime loss, spectral response, and beam hardening effects'. Together they form a unique fingerprint.

Cite this