TY - GEN
T1 - Theoretical comparison and optimization of CdTe and GaAs photon-counting detectors for contrast-enhanced spectral mammography
AU - Schaeffer, Colin
AU - Ghammraoui, Bahaa
AU - Taguchi, Katsuyuki
AU - Glick, Stephen
N1 - Publisher Copyright:
© 2022 SPIE.
PY - 2022
Y1 - 2022
N2 - There has recently been renewed interest in quantitative iodinated contrast-enhanced breast imaging, sometimes referred to as contrast-enhanced spectral mammography (CESM). Photon-counting detectors (PCDs) have a number of benefits for iodinated contrast-enhanced imaging over dual-energy systems (using energy integrating detectors), one of which is the capability of acquiring multi-bin data with one exposure. Most PCDs and prototype systems being developed are using CdTe or CZT sensor material which have non-optimal characteristic X-ray emission with energies in the range used for breast imaging. This increases charge sharing and, hence, spectral degradation. Recently, a new PCD has been developed using a GaAs sensor. Since GaAs has lower energy characteristic x-rays (lower than CdTe), it is expected that this new PCD detector might be beneficial for spectral x-ray breast imaging. In this work, we have theoretically compared the two detector materials in terms of iodine quantification using the Cramer-Rao lower bound (CRLB) as a figure of merit. Four different experiments were performed, each comparing the performance of CdTe and GaAs: 1) sensitivity of iodine quantification to charge cloud size and electronic noise, 2) effect of dose and photon spectrum on iodine quantification, 3) how the CRLB changes with the number of energy bins, and 4) a dose analysis study to assess any possible dose reduction offered by either detector. Simulations of both the CdTe and GaAs PCDs were performed using the Photon Counting Toolkit (PcTK) software. Three sets of 5000 noise realizations were used to calculate the CRLB of iodine quantification in each study.
AB - There has recently been renewed interest in quantitative iodinated contrast-enhanced breast imaging, sometimes referred to as contrast-enhanced spectral mammography (CESM). Photon-counting detectors (PCDs) have a number of benefits for iodinated contrast-enhanced imaging over dual-energy systems (using energy integrating detectors), one of which is the capability of acquiring multi-bin data with one exposure. Most PCDs and prototype systems being developed are using CdTe or CZT sensor material which have non-optimal characteristic X-ray emission with energies in the range used for breast imaging. This increases charge sharing and, hence, spectral degradation. Recently, a new PCD has been developed using a GaAs sensor. Since GaAs has lower energy characteristic x-rays (lower than CdTe), it is expected that this new PCD detector might be beneficial for spectral x-ray breast imaging. In this work, we have theoretically compared the two detector materials in terms of iodine quantification using the Cramer-Rao lower bound (CRLB) as a figure of merit. Four different experiments were performed, each comparing the performance of CdTe and GaAs: 1) sensitivity of iodine quantification to charge cloud size and electronic noise, 2) effect of dose and photon spectrum on iodine quantification, 3) how the CRLB changes with the number of energy bins, and 4) a dose analysis study to assess any possible dose reduction offered by either detector. Simulations of both the CdTe and GaAs PCDs were performed using the Photon Counting Toolkit (PcTK) software. Three sets of 5000 noise realizations were used to calculate the CRLB of iodine quantification in each study.
KW - breast imaging
KW - photon counting detectors
KW - spectral imaging
UR - http://www.scopus.com/inward/record.url?scp=85131173621&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85131173621&partnerID=8YFLogxK
U2 - 10.1117/12.2611134
DO - 10.1117/12.2611134
M3 - Conference contribution
AN - SCOPUS:85131173621
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Medical Imaging 2022
A2 - Zhao, Wei
A2 - Yu, Lifeng
PB - SPIE
T2 - Medical Imaging 2022: Physics of Medical Imaging
Y2 - 21 March 2022 through 27 March 2022
ER -