TY - GEN
T1 - Enabling photon counting detectors with dynamic attenuators
AU - Hsieh, Scott S.
AU - Pelc, Norbert J.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014
Y1 - 2014
N2 - Photon-counting x-ray detectors (PCXDs) are being investigated as a replacement for conventional x-ray detectors because they promise several advantages, including better dose efficiency, higher resolution and spectral imaging. However, many of these advantages disappear when the x-ray flux incident on the detector is too high. We recently proposed a dynamic, piecewise-linear attenuator (or beam shaping filter) that can control the flux incident on the detector. This can restrict the operating range of the PCXD to keep the incident count rate below a given limit. We simulated a system with the piecewise-linear attenuator and a PCXD using raw data generated from forward projected DICOM files. We investigated the classic paralyzable and nonparalyzable PCXD as well as a weighted average of the two, with the weights chosen to mimic an existing PCXD (Taguchi et al, Med Phys 2011). The dynamic attenuator has small synergistic benefits with the nonparalyzable detector and large synergistic benefits with the paralyzable detector. Real PCXDs operate somewhere between these models, and the weighted average model still shows large benefits from the dynamic attenuator. We conclude that dynamic attenuators can reduce the count rate performance necessary for adopting PCXDs.
AB - Photon-counting x-ray detectors (PCXDs) are being investigated as a replacement for conventional x-ray detectors because they promise several advantages, including better dose efficiency, higher resolution and spectral imaging. However, many of these advantages disappear when the x-ray flux incident on the detector is too high. We recently proposed a dynamic, piecewise-linear attenuator (or beam shaping filter) that can control the flux incident on the detector. This can restrict the operating range of the PCXD to keep the incident count rate below a given limit. We simulated a system with the piecewise-linear attenuator and a PCXD using raw data generated from forward projected DICOM files. We investigated the classic paralyzable and nonparalyzable PCXD as well as a weighted average of the two, with the weights chosen to mimic an existing PCXD (Taguchi et al, Med Phys 2011). The dynamic attenuator has small synergistic benefits with the nonparalyzable detector and large synergistic benefits with the paralyzable detector. Real PCXDs operate somewhere between these models, and the weighted average model still shows large benefits from the dynamic attenuator. We conclude that dynamic attenuators can reduce the count rate performance necessary for adopting PCXDs.
KW - dynamic bowtie
KW - dynamic range reduction
KW - exposure control
KW - photon counting detector
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U2 - 10.1117/12.2042533
DO - 10.1117/12.2042533
M3 - Conference contribution
AN - SCOPUS:84901611427
SN - 9780819498267
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Medical Imaging 2014
PB - SPIE
T2 - Medical Imaging 2014: Physics of Medical Imaging
Y2 - 17 February 2014 through 20 February 2014
ER -