TY - JOUR
T1 - Dual-source photon counting detector CT with a tin filter
T2 - A phantom study on iodine quantification performance
AU - Tao, Ashley
AU - Huang, Richard
AU - Tao, Shengzhen
AU - Michalak, Gregory J.
AU - McCollough, Cynthia H.
AU - Leng, Shuai
N1 - Publisher Copyright:
© 2019 Institute of Physics and Engineering in Medicine.
PY - 2019
Y1 - 2019
N2 - Photon counting detectors (PCD) can provide spectral information to enable iodine quantification through multi-energy imaging but performance is limited by current PCD technology. The purpose of this work is to evaluate iodine quantification in a phantom study using dual-source PCD-CT (DS-PCD-CT), and compare to single-source (SS)-PCD-CT and traditional DS energy integrating detector (EID)-based dual-energy CT. A multi-energy CT phantom with iodine inserts (0 to 15 mg ml-1 concentration) was imaged on a research SS-PCD-CT scanner (CTDIvol = 18 mGy). A DS-PCD-CT was emulated by acquiring two sequential scans (CTDIvol = 9 mGy each) using tube potentials: 140 kVp/80 kVp, 140 kVp/100 kVp and 140 kVp/120 kVp. For each kVp, 1 or 2 energy bins were reconstructed to achieve either dual-energy or quadruple energy CT. In addition to these energy combinations, a Sn filter was used for the high tube potential (140 kVp) of each kVp pair. For comparison, the same phantom was also scanned on a commercially available DS-EID-CT with matched radiation dose (CTDIvol = 18 mGy). Material decomposition was performed in image space using a standard least-squares based approach to generate iodine and water-specific images. The root-mean-square-error (RMSE) measured over each insert from the iodine image was used to determine iodine accuracy. The iodine RMSE from SS-PCD (140 kVp with 2 energy bins) was 2.72 mg ml-1. The use of a DS configuration with 1 energy bin per kVp (140 kVp/80 kVp) resulted in a RMSE of 2.29 mg ml-1. Two energy bins per kVp further reduced iodine RMSE to 1.83 mg ml-1. The addition of a Sn filter to the latter quadruple energy mode reduced RMSE to 1.48 mg ml-1. RMSE for DS-PCD-CT (2 energy bins per kVp) decreased by 1.3% (Sn140 kVp/80 kVp) and 15% (Sn140 kVp/100 kVp) as compared to DS-EID-CT. DS-PCD-CT with a Sn filter improved iodine quantification as compared to both SS-PCD-CT and DS-EID-CT.
AB - Photon counting detectors (PCD) can provide spectral information to enable iodine quantification through multi-energy imaging but performance is limited by current PCD technology. The purpose of this work is to evaluate iodine quantification in a phantom study using dual-source PCD-CT (DS-PCD-CT), and compare to single-source (SS)-PCD-CT and traditional DS energy integrating detector (EID)-based dual-energy CT. A multi-energy CT phantom with iodine inserts (0 to 15 mg ml-1 concentration) was imaged on a research SS-PCD-CT scanner (CTDIvol = 18 mGy). A DS-PCD-CT was emulated by acquiring two sequential scans (CTDIvol = 9 mGy each) using tube potentials: 140 kVp/80 kVp, 140 kVp/100 kVp and 140 kVp/120 kVp. For each kVp, 1 or 2 energy bins were reconstructed to achieve either dual-energy or quadruple energy CT. In addition to these energy combinations, a Sn filter was used for the high tube potential (140 kVp) of each kVp pair. For comparison, the same phantom was also scanned on a commercially available DS-EID-CT with matched radiation dose (CTDIvol = 18 mGy). Material decomposition was performed in image space using a standard least-squares based approach to generate iodine and water-specific images. The root-mean-square-error (RMSE) measured over each insert from the iodine image was used to determine iodine accuracy. The iodine RMSE from SS-PCD (140 kVp with 2 energy bins) was 2.72 mg ml-1. The use of a DS configuration with 1 energy bin per kVp (140 kVp/80 kVp) resulted in a RMSE of 2.29 mg ml-1. Two energy bins per kVp further reduced iodine RMSE to 1.83 mg ml-1. The addition of a Sn filter to the latter quadruple energy mode reduced RMSE to 1.48 mg ml-1. RMSE for DS-PCD-CT (2 energy bins per kVp) decreased by 1.3% (Sn140 kVp/80 kVp) and 15% (Sn140 kVp/100 kVp) as compared to DS-EID-CT. DS-PCD-CT with a Sn filter improved iodine quantification as compared to both SS-PCD-CT and DS-EID-CT.
KW - dual-source CT
KW - iodine quantification
KW - multi-energy CT
KW - photon counting detector CT
KW - spectral separation
KW - tin filter
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U2 - 10.1088/1361-6560/ab1c34
DO - 10.1088/1361-6560/ab1c34
M3 - Article
C2 - 31018197
AN - SCOPUS:85067268596
SN - 0031-9155
VL - 64
JO - Physics in medicine and biology
JF - Physics in medicine and biology
IS - 11
M1 - 115019
ER -