Modeling photon-counting detectors for x-ray CT: Spectral response and pulse-pileup effects and evaluation using real data

J. Cammin, J. Xu, W. C. Barber, J. S. Iwanczyk, N. E. Hartsough, Katsuyuki Taguchi

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

Abstract

Spectral computed tomography (CT) with photon-counting detectors (PCDs) has the potential to substantially advance diagnostic CT imaging by reducing image noise and dose to the patient, by improving contrast and tissue specificity, and by enabling molecular and functional imaging. The current PCD technology, however, is limited by two main factors: imperfect energy measurement (spectral response effects, SRE) and limited count rate (pulse-pileup effects, PPE, due to detector dead-times). The overall goal of our research is to develop compensation algorithms for these sources of data distortions, to demonstrate that PCDs are suitable for clinical CT, and to identify key clinical applications for spectral CT with PCDs. We have already developed an iterative compensation scheme that includes a forward projection model of the imaging chain and that can compensate for either SRE or PPE distortions separately by maximizing a penalized log-likelihood function. In this paper we describe the evaluation of a combined, cascaded SRE and PPE model for PCDs and compare the models to data acquired with an experimental table-top PCD-CT system. The separation into count-rate independent effects (SRE) and count-rate dependent effects (PPE) allows cascading the forward model. First, the SRE model is evaluated using low count rates. Then the PPE model is cascaded and the combined SRE+PPE model is evaluated. Several different attenuators were used, including K-edge materials and the models and data were compared for various count-rate conditions.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume8668
DOIs
StatePublished - 2013
EventMedical Imaging 2013: Physics of Medical Imaging - Lake Buena Vista, FL, United States
Duration: Feb 11 2013Feb 14 2013

Other

OtherMedical Imaging 2013: Physics of Medical Imaging
CountryUnited States
CityLake Buena Vista, FL
Period2/11/132/14/13

Fingerprint

spectral sensitivity
Photons
Tomography
counting
tomography
X-Rays
Detectors
X rays
evaluation
detectors
photons
pulses
x rays
Imaging techniques
Likelihood Functions
Organ Specificity
Molecular Imaging
Information Storage and Retrieval
Electric power measurement
pulse rate

Keywords

  • Computed tomography
  • Photon-counting detectors
  • Pulse-pileup
  • Spectral response

ASJC Scopus subject areas

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

Cite this

Cammin, J., Xu, J., Barber, W. C., Iwanczyk, J. S., Hartsough, N. E., & Taguchi, K. (2013). Modeling photon-counting detectors for x-ray CT: Spectral response and pulse-pileup effects and evaluation using real data. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 8668). [86680R] https://doi.org/10.1117/12.2008077

Modeling photon-counting detectors for x-ray CT : Spectral response and pulse-pileup effects and evaluation using real data. / Cammin, J.; Xu, J.; Barber, W. C.; Iwanczyk, J. S.; Hartsough, N. E.; Taguchi, Katsuyuki.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 8668 2013. 86680R.

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

Cammin, J, Xu, J, Barber, WC, Iwanczyk, JS, Hartsough, NE & Taguchi, K 2013, Modeling photon-counting detectors for x-ray CT: Spectral response and pulse-pileup effects and evaluation using real data. in Progress in Biomedical Optics and Imaging - Proceedings of SPIE. vol. 8668, 86680R, Medical Imaging 2013: Physics of Medical Imaging, Lake Buena Vista, FL, United States, 2/11/13. https://doi.org/10.1117/12.2008077
Cammin J, Xu J, Barber WC, Iwanczyk JS, Hartsough NE, Taguchi K. Modeling photon-counting detectors for x-ray CT: Spectral response and pulse-pileup effects and evaluation using real data. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 8668. 2013. 86680R https://doi.org/10.1117/12.2008077
Cammin, J. ; Xu, J. ; Barber, W. C. ; Iwanczyk, J. S. ; Hartsough, N. E. ; Taguchi, Katsuyuki. / Modeling photon-counting detectors for x-ray CT : Spectral response and pulse-pileup effects and evaluation using real data. Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 8668 2013.
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