TY - JOUR
T1 - Novel anthropomorphic hip phantom corrects systemic interscanner differences in proximal femoral vBMD
AU - Bonaretti, S.
AU - Carpenter, R. D.
AU - Saeed, I.
AU - Burghardt, A. J.
AU - Yu, L.
AU - Bruesewitz, M.
AU - Khosla, S.
AU - Lang, T.
N1 - Publisher Copyright:
© 2014 Institute of Physics and Engineering in Medicine.
PY - 2014/12/21
Y1 - 2014/12/21
N2 - Quantitative computed tomography (QCT) is increasingly used in osteoporosis studies to assess volumetric bone mineral density (vBMD), bone quality and strength. However, QCT is confronted by technical issues in the clinical research setting, such as potentially confounding effects of body size on vBMD measurements and lack of standard approaches to scanner cross-calibration, which affects measurements of vBMD in multicenter settings. In this study, we addressed systematic inter-scanner differences and subject-dependent body size errors using a novel anthropomorphic hip phantom, containing a calibration hip to estimate correction equations, and a contralateral test hip to assess the quality of the correction. We scanned this phantom on four different scanners and we applied phantom-derived corrections to in vivo images of 16 postmenopausal women scanned on two scanners. From the phantom study, we found that vBMD decreased with increasing phantom size in three of four scanners and that inter-scanner variations increased with increasing phantom size. In the in vivo study, we observed that inter-scanner corrections reduced systematic inter-scanner mean vBMD differences but that the inter-scanner precision error was still larger than expected from known intra-scanner precision measurements. In conclusion, inter-scanner corrections and body size influence should be considered when measuring vBMD from QCT images.
AB - Quantitative computed tomography (QCT) is increasingly used in osteoporosis studies to assess volumetric bone mineral density (vBMD), bone quality and strength. However, QCT is confronted by technical issues in the clinical research setting, such as potentially confounding effects of body size on vBMD measurements and lack of standard approaches to scanner cross-calibration, which affects measurements of vBMD in multicenter settings. In this study, we addressed systematic inter-scanner differences and subject-dependent body size errors using a novel anthropomorphic hip phantom, containing a calibration hip to estimate correction equations, and a contralateral test hip to assess the quality of the correction. We scanned this phantom on four different scanners and we applied phantom-derived corrections to in vivo images of 16 postmenopausal women scanned on two scanners. From the phantom study, we found that vBMD decreased with increasing phantom size in three of four scanners and that inter-scanner variations increased with increasing phantom size. In the in vivo study, we observed that inter-scanner corrections reduced systematic inter-scanner mean vBMD differences but that the inter-scanner precision error was still larger than expected from known intra-scanner precision measurements. In conclusion, inter-scanner corrections and body size influence should be considered when measuring vBMD from QCT images.
KW - anthropomorphic hip phantom
KW - body size
KW - bone mineral density
KW - inter-scanner differences
KW - quantitative computed tomography
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U2 - 10.1088/0031-9155/59/24/7819
DO - 10.1088/0031-9155/59/24/7819
M3 - Article
C2 - 25419618
AN - SCOPUS:84924402116
SN - 0031-9155
VL - 59
SP - 7819
EP - 7834
JO - Physics in medicine and biology
JF - Physics in medicine and biology
IS - 24
ER -