TY - JOUR
T1 - Variability of CT Attenuation Measurements in Virtual Unenhanced Images Generated Using Multimaterial Decomposition from Fast Kilovoltage-switching Dual-energy CT
AU - Kaza, Ravi K.
AU - Raff, Evan A.
AU - Davenport, Matthew S.
AU - Khalatbari, Shokoufeh
N1 - Funding Information:
Statistical analysis was performed with financial support from the National Institutes of Health grant UL1TR000433.
Publisher Copyright:
© 2017 The Association of University Radiologists
PY - 2017/3/1
Y1 - 2017/3/1
N2 - Rationale and Objectives To compare Hounsfield unit (HU) data obtained from true-unenhanced (TUE) and virtual-unenhanced (VUE) imaging obtained with a fast kv-switching dual-energy computed tomography (CT) scanner using multimaterial decomposition algorithm. Materials and Methods In this Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective cohort study, CT scans of 19 patients undergoing multiphasic renal protocol abdominal CT on a fast kv-switching dual-energy CT scanner were reviewed. CT numbers were measured on the matched TUE and VUE generated using a multimaterial decomposition algorithm with selective iodine suppression, and postcontrast images at predefined locations in seven organs. Six hundred sixty regions of interest were placed at 132 locations. Agreement was assessed with paired t test, Pearson's correlation, and Bland-Altman analysis. Results Mean TUE and VUE measurements were not significantly different in the corticomedullary (P = 0.25) or nephrographic (P = 0.10) phases. There was a strong correlation between TUE and VUE CT numbers (corticomedullary: r = 0.90, nephrographic: r = 0.90, each P < 0.001). Discrepancies ≥5 HU occurred 46 times (35%, 46 of 132) in the corticomedullary phase and 44 times (33%, 44 of 132) in the nephrographic phase. Discrepancies ≥10 HU occurred in 7% (9 of 132 in both corticomedullary and nephrographic phases). Interphase, intrasubject VUE CT numbers were strongly correlated (r = 0.93, P < 0.001), but discrepancies ≥5 HU (22% [29 of 132]) and ≥10 HU (2% [3 of 132]) occurred. There was no significant correlation between the true postcontrast CT number and the magnitude of VUE-TUE discrepancy (r = −0.04, P = 0.6). Conclusion CT numbers on VUE images generated from fast kv-switching dual-energy CT scans strongly correlate with TUE CT numbers on a population basis, but commonly vary 5–9 HU on a per-patient basis.
AB - Rationale and Objectives To compare Hounsfield unit (HU) data obtained from true-unenhanced (TUE) and virtual-unenhanced (VUE) imaging obtained with a fast kv-switching dual-energy computed tomography (CT) scanner using multimaterial decomposition algorithm. Materials and Methods In this Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective cohort study, CT scans of 19 patients undergoing multiphasic renal protocol abdominal CT on a fast kv-switching dual-energy CT scanner were reviewed. CT numbers were measured on the matched TUE and VUE generated using a multimaterial decomposition algorithm with selective iodine suppression, and postcontrast images at predefined locations in seven organs. Six hundred sixty regions of interest were placed at 132 locations. Agreement was assessed with paired t test, Pearson's correlation, and Bland-Altman analysis. Results Mean TUE and VUE measurements were not significantly different in the corticomedullary (P = 0.25) or nephrographic (P = 0.10) phases. There was a strong correlation between TUE and VUE CT numbers (corticomedullary: r = 0.90, nephrographic: r = 0.90, each P < 0.001). Discrepancies ≥5 HU occurred 46 times (35%, 46 of 132) in the corticomedullary phase and 44 times (33%, 44 of 132) in the nephrographic phase. Discrepancies ≥10 HU occurred in 7% (9 of 132 in both corticomedullary and nephrographic phases). Interphase, intrasubject VUE CT numbers were strongly correlated (r = 0.93, P < 0.001), but discrepancies ≥5 HU (22% [29 of 132]) and ≥10 HU (2% [3 of 132]) occurred. There was no significant correlation between the true postcontrast CT number and the magnitude of VUE-TUE discrepancy (r = −0.04, P = 0.6). Conclusion CT numbers on VUE images generated from fast kv-switching dual-energy CT scans strongly correlate with TUE CT numbers on a population basis, but commonly vary 5–9 HU on a per-patient basis.
KW - Dual-energy CT
KW - multimaterial decomposition
KW - Virtual unenhanced imaging
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U2 - 10.1016/j.acra.2016.09.002
DO - 10.1016/j.acra.2016.09.002
M3 - Article
C2 - 27769822
AN - SCOPUS:85006046052
SN - 1076-6332
VL - 24
SP - 365
EP - 372
JO - Academic radiology
JF - Academic radiology
IS - 3
ER -