Asynchronous calibration could allow opportunistic screening based on routine CT for early osteoporosis detection. In this phantom study, a bone mineral density (BMD) calibration phantom and multi-energy CT (MECT) phantom were imaged on eight different CT scanners with multiple tube voltages (80–150 kV_p) and image reconstruction settings (e.g. soft/hard kernel). Reference values for asynchronous BMD estimation were calculated from the BMD-phantom and validated with six calcium composite inserts of the MECT-phantom with known ground truth. Relative errors/changes in estimated BMD were calculated and investigated for influence of tube voltage, CT scanner and reconstruction setting. Reference values for 282 acquisitions were determined, resulting in an average relative error between calculated BMD and ground truth of − 9.2% ± 14.0% with a strong correlation (R² = 0.99; p < 0.0001). Tube voltage and CT scanner had a significant effect on calculated BMD (p < 0.0001), with relative differences in BMD of 3.8% ± 28.2% when adapting reference values for tube voltage, − 5.6% ± 9.2% for CT scanner and 0.2% ± 0.2% for reconstruction setting, respectively. Differences in BMD were small when using reference values from a different CT scanner of the same model (0.0% ± 1.4%). Asynchronous phantom-based calibration is feasible for opportunistic BMD assessment based on CT images with reference values adapted for tube voltage and CT scanner model.

异步校准可以允许基于常规 CT 的机会性筛查进行早期骨质疏松症检测。在这项体模研究中，骨矿物质密度 (BMD) 校准体模和多能 CT (MECT) 体模在八种不同的 CT 扫描仪上成像，具有多个管电压（80–150 kV _p) 和图像重建设置（例如软/硬内核）。异步 BMD 估计的参考值是根据 BMD 模型计算的，并用 MECT 模型的六个钙复合插入物和已知的基本事实进行了验证。计算估计 BMD 的相对误差/变化，并研究管电压、CT 扫描仪和重建设置的影响。确定了 282 次采集的参考值，导致计算的 BMD 和地面真实值之间的平均相对误差为 − 9.2% ± 14.0%，具有很强的相关性 ( R ²  = 0.99；p  < 0.0001)。管电压和 CT 扫描仪对计算的 BMD 有显着影响 ( p < 0.0001)，当调整管电压的参考值时，BMD 的相对差异为 3.8% ± 28.2%，CT 扫描仪为 − 5.6% ± 9.2%，重建设置为 0.2% ± 0.2%，分别。当使用同一型号不同 CT 扫描仪的参考值时，BMD 的差异很小 (0.0% ± 1.4%)。基于具有适用于管电压和 CT 扫描仪模型的参考值的 CT 图像，基于异步模型的校准对于机会主义 BMD 评估是可行的。