Photon-counting CT: Modeling and compensating of spectral distortion effects

Jochen Cammin, Steffen Kappler, Thomas Weidinger, 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. However, the current PCD technology is limited by two main factors: imperfect energy measurement (spectral response effects, SR) and count rate non-linearity (pulse pileup effects, PP, due to detector deadtimes) resulting in image artifacts and quantitative inaccuracies for material specification. These limitations can be lifted with image reconstruction algorithms that compensate for both SR and PP. A prerequisite for this approach is an accurate model of the count losses and spectral distortions in the PCD. In earlier work we developed a cascaded SR-PP model and evaluated it using a physical PCD. In this paper we show the robustness of our approach by modifying the cascaded SR-PP model for a faster PCD with smaller pixels and a different pulse shape. We compare paralyzable and non-paralyzable detector models. First, the SR-PP model is evaluated at low and high count rates using two sets of attenuators. Then, the accuracy of the compensation is evaluated by estimating the thicknesses of three basis functions.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2015: Physics of Medical Imaging
PublisherSPIE
Volume9412
ISBN (Print)9781628415025
DOIs
StatePublished - 2015
EventMedical Imaging 2015: Physics of Medical Imaging - Orlando, United States
Duration: Feb 22 2015Feb 25 2015

Other

OtherMedical Imaging 2015: Physics of Medical Imaging
CountryUnited States
CityOrlando
Period2/22/152/25/15

Fingerprint

Photons
Tomography
counting
tomography
spectral sensitivity
Detectors
detectors
photons
Organ Specificity
Molecular Imaging
Computer-Assisted Image Processing
Artifacts
Imaging techniques
Electric power measurement
attenuators
image reconstruction
pulses
Image reconstruction
Technology
artifacts

Keywords

  • Compensation of spectral distortions
  • Computed tomography
  • Nonparalyzable detector
  • Paralyzable detector
  • Photon counting
  • 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., Kappler, S., Weidinger, T., & Taguchi, K. (2015). Photon-counting CT: Modeling and compensating of spectral distortion effects. In Medical Imaging 2015: Physics of Medical Imaging (Vol. 9412). [941250] SPIE. https://doi.org/10.1117/12.2080849

Photon-counting CT : Modeling and compensating of spectral distortion effects. / Cammin, Jochen; Kappler, Steffen; Weidinger, Thomas; Taguchi, Katsuyuki.

Medical Imaging 2015: Physics of Medical Imaging. Vol. 9412 SPIE, 2015. 941250.

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

Cammin, J, Kappler, S, Weidinger, T & Taguchi, K 2015, Photon-counting CT: Modeling and compensating of spectral distortion effects. in Medical Imaging 2015: Physics of Medical Imaging. vol. 9412, 941250, SPIE, Medical Imaging 2015: Physics of Medical Imaging, Orlando, United States, 2/22/15. https://doi.org/10.1117/12.2080849
Cammin J, Kappler S, Weidinger T, Taguchi K. Photon-counting CT: Modeling and compensating of spectral distortion effects. In Medical Imaging 2015: Physics of Medical Imaging. Vol. 9412. SPIE. 2015. 941250 https://doi.org/10.1117/12.2080849
Cammin, Jochen ; Kappler, Steffen ; Weidinger, Thomas ; Taguchi, Katsuyuki. / Photon-counting CT : Modeling and compensating of spectral distortion effects. Medical Imaging 2015: Physics of Medical Imaging. Vol. 9412 SPIE, 2015.
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