Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany.
Division of Experimental Imaging, Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany.
Eur J Radiol. 2020 Nov;132:109321. doi: 10.1016/j.ejrad.2020.109321. Epub 2020 Sep 28.
To assess the diagnostic accuracy of phantomless dual-energy computed tomography (DECT)-based volumetric material decomposition to assess bone mineral density (BMD) of the lumbar spine for the detection of osteoporosis compared to Hounsfield unit (HU) measurements with dual x-ray absorptiometry (DXA) as reference standard.
A total of two hundred lumbar vertebrae in 53 patients (28 men, 25 women; mean age, 52 years, range, 23-87 years) who had undergone clinically-indicated third-generation dual-source DECT and DXA within 30 days were retrospectively analyzed. For volumetric BMD assessment, dedicated DECT postprocessing software using material decomposition was applied, which enables color-coded three-dimensional mapping of the trabecular BMD distribution. Manual HU measurements were performed by defining five trabecular regions of interest (ROI) per vertebra as suggested by literature. The DXA T-score served as standard of reference (osteoporosis: T < -2.5). Sensitivity, specificity and the area under the curve (AUC) were primary metrics of diagnostic accuracy.
An optimal patient-based DECT-derived BMD cut-off of 84 mg/cm³ yielded 96 % sensitivity (22/23) and 93 % specificity (28/30) for detecting osteoporosis, while an optimal CT attenuation cut-off of 139 HU showed 65 % sensitivity (15/23) and 93 % specificity (28/30) for the detection of osteoporosis. Overall patient-based AUC were 0.930 (volumetric DECT) and 0.790 (HU analysis) (p < .001). Pearson's product-moment correlation showed higher correlation between DECT BMD and DXA values (r=0.780) compared to HU and DXA values (r=0.528) (p < .001).
Phantomless volumetric DECT yielded significantly more accurate BMD assessment of the lumbar spine and superior diagnostic accuracy of osteoporosis compared to HU measurements.
评估无模体双能 CT（DECT）基于容积物质分解的诊断准确性，以评估腰椎骨矿物质密度（BMD），与双能 X 线吸收法（DXA）作为参考标准的 Hounsfield 单位（HU）测量相比，用于骨质疏松症的检测。
回顾性分析了 53 例（28 名男性，25 名女性；平均年龄 52 岁，范围 23-87 岁）患者，这些患者在 30 天内接受了临床指征明确的第三代双源 DECT 和 DXA 检查。为了评估容积 BMD，使用专用的 DECT 后处理软件进行物质分解，该软件可对小梁 BMD 分布进行彩色三维映射。根据文献建议，对每个椎体的 5 个小梁感兴趣区（ROI）进行手动 HU 测量。DXA T 评分作为参考标准（骨质疏松症：T < -2.5）。敏感性、特异性和曲线下面积（AUC）是诊断准确性的主要指标。
基于患者的最佳 DECT 衍生 BMD 截断值为 84mg/cm³，可检测出 96%的骨质疏松症（22/23），特异性为 93%（28/30），而最佳 CT 衰减截断值为 139HU 时，敏感性为 65%（15/23），特异性为 93%（28/30）。总体患者基于 AUC 为 0.930（容积 DECT）和 0.790（HU 分析）（p < 0.001）。Pearson 积矩相关显示，DECT BMD 与 DXA 值的相关性高于 HU 与 DXA 值的相关性（r=0.780 比 r=0.528）（p < 0.001）。
与 HU 测量相比，无模体容积 DECT 可更准确地评估腰椎 BMD，对骨质疏松症的诊断准确性更高。
