Los Angeles Biomedical Research Institute at Harbor UCLA, Torrance, CA 90502, USA.
Acad Radiol. 2012 Feb;19(2):179-83. doi: 10.1016/j.acra.2011.10.006. Epub 2011 Nov 23.
To evaluate the agreement of bone mineral density (BMD) between lumbar (L) and individual thoracic (T) vertebrae and identify a standard thoracic spine level for BMD assessment in cardiac computed tomography (CT) images.
Three hundred subjects who underwent simultaneous chest and abdomen CT scans for clinical indications were included. A calibration phantom that extended from the first thoracic spine (T(1)) to the fifth lumbar (L(5)) was employed. Vertebral BMD were measured by QCT 5000 and NVivo systems. The association between three consecutive lumbar (L1-L3) and thoracic BMD (3T, initiation site equivalent to left main coronary caudally) was evaluated.
There was a gradual decrease in BMD values from T(1) to L(3,) subsequently increasing in L(4) and L(5) in both genders. When stratified by gender, 3T BMD was significantly higher versus L(1-3) BMD (156.9 versus 141.9vmg/cm(3), P < .001) for women as well as for men (164.8 versus 151.0 mg/cm(3), P < .001). There is good correlation between 3T and L(1-3) BMD, the Pearson's correlation coefficients are 0.91 and 0.93 for women and men, respectively. We further analyzed the associations between L(1-3) and any individual spine of T(1)-L(5) and similar relationships were observed (r value, 0.62-0.98). The intraobserver, interobserver, and interscan variation measurement of thoracic quantitative CT was 2.5 (1.0, 95% CI 0.099-1.004); 2.6 (1.0, 95CI% 0.992-1.007), and 2.8% (1.0,95% 0.0994-1.008), respectively.
The 3T BMD was highly correlated with L(1-3) BMD. Thoracic BMD can be measured during cardiac and lung CT imaging without need for additional participant burden or radiation dose. This highly reproducible methodology is actively being applied to large cohort studies to evaluate the prevalence of osteoporosis and track BMD over time.
评估腰椎（L）和各个胸椎（T）之间骨密度（BMD）的一致性，并确定心脏 CT（CT）图像中 BMD 评估的标准胸椎水平。
本研究纳入了 300 例因临床指征同时接受胸部和腹部 CT 扫描的患者。使用从第一胸椎（T1）延伸至第五腰椎（L5）的校准体模。通过 QCT 5000 和 NVivo 系统测量椎体 BMD。评估了三个连续的腰椎（L1-L3）和胸椎（T3，起始部位相当于左主冠状动脉的尾侧）BMD 之间的相关性。
在男女两性中，BMD 值从 T1 逐渐降低至 L3，随后在 L4 和 L5 增加。按性别分层，女性（164.8 比 151.0mg/cm³，P＜0.001）和男性（164.8 比 151.0mg/cm³，P＜0.001）3T 与 L1-3 的 BMD 相比均显著升高。3T 与 L1-3 的 BMD 之间具有良好的相关性，女性和男性的 Pearson 相关系数分别为 0.91 和 0.93。我们进一步分析了 L1-3 与 T1-L5 之间任何单个胸椎的相关性，观察到类似的相关性（r 值为 0.62-0.98）。胸椎定量 CT 的观察者内、观察者间和扫描间变异的测量值分别为 2.5（1.0，95%CI 0.099-1.004）；2.6（1.0，95%CI 0.992-1.007）和 2.8%（1.0，95%CI 0.0994-1.008）。
3T 的 BMD 与 L1-3 的 BMD 高度相关。在心脏和肺部 CT 成像期间，可以测量胸椎 BMD，而无需增加患者负担或辐射剂量。这种高度可重复的方法正在积极应用于大型队列研究中，以评估骨质疏松症的患病率并跟踪随时间的 BMD 变化。
