Clinic for Diagnostic and Interventional Radiology (DIR), Heidelberg University Hospital, Heidelberg, Germany.
Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik, University of Heidelberg, Heidelberg, Germany.
Eur J Radiol. 2024 Sep;178:111606. doi: 10.1016/j.ejrad.2024.111606. Epub 2024 Jul 6.
To evaluate a novel calcium-only imaging technique (VCa) with subtracted bone marrow in osteoporosis in dual-layer CT (DLCT) compared to conventional CT images (CI) and dual-energy X-ray absorptiometry (DXA).
Images of a multi-energy CT phantom with calcium inserts, quantitative CT calibration phantom, and of 55 patients (mean age: 64.6 ± 11.5 years) were acquired on a DLCT to evaluate bone mineral density (BMD). CI, calcium-suppressed images, and VCa were calculated. For investigating the association of VCa and CI with DXA a subsample of 30 patients (<90 days between DXA and CT) was used. Multiple regression analysis was performed to identify further factors improving the prediction of DXA BMD.
The calcium concentrations of the CT phantom inserts were significantly associated with CT numbers from VCa (R = 0.94) and from CI (R = 0.89-0.92). VCa showed significantly higher CT numbers than CI in the phantom (p ≤ 0.001) and clinical setting (p < 0.001). CT numbers from VCa were significantly associated with CI (R = 0.95, p < 0.001) and with DXA (R = 0.31, p = 0.007), whereas no significant association between DXA and CI was found. Prediction of DXA BMD based on CT numbers derived from VCa yielded R = 0.76 in multiple regression analysis. ROC for the differentiation of normal from pathologic BMD in VCa yielded an AUC of 0.7, and a cut-off value of 126HU (sensitivity: 0.90; specificity: 0.47).
VCa images showed better agreement with DXA and known calcium concentrations than CI, and could be used to estimate BMD. A VCa cut-off of 126HU could be used to identify abnormal bone mineral density.
在双层 CT（DLCT）中，与常规 CT 图像（CI）和双能 X 射线吸收法（DXA）相比，评估一种新型仅含钙的成像技术（VCa）与骨髓抑制在骨质疏松症中的应用。
使用 DLCT 对多能量 CT 体模、定量 CT 校准体模和 55 例患者（平均年龄：64.6±11.5 岁）的图像进行采集，以评估骨矿物质密度（BMD）。计算 CI、钙抑制图像和 VCa。为了研究 VCa 和 CI 与 DXA 的相关性，使用了 30 例患者的子样本（DXA 和 CT 之间的时间间隔<90 天）。采用多元回归分析来确定改善 DXA BMD 预测的其他因素。
CT 体模插入物的钙浓度与 VCa（R=0.94）和 CI（R=0.89-0.92）的 CT 数显著相关。VCa 在体模（p≤0.001）和临床环境（p<0.001）中比 CI 显示出更高的 CT 数。VCa 的 CT 数与 CI（R=0.95，p<0.001）和 DXA（R=0.31，p=0.007）显著相关，而 DXA 与 CI 之间无显著相关性。基于 VCa 得出的 CT 数预测 DXA BMD 的多元回归分析中 R=0.76。在 VCa 中，正常和病理性 BMD 之间的区分的 ROC 曲线产生了 0.7 的 AUC，126HU 的截断值（敏感性：0.90；特异性：0.47）。
VCa 图像与 DXA 和已知的钙浓度的一致性优于 CI，可用于估计 BMD。VCa 的 126HU 截断值可用于识别异常的骨矿物质密度。
