■一项回顾性研究。
■研究通过胸部计算机断层扫描(CT)测量的Hounsfield单位(HU)值与双能X射线吸收法(DXA)T评分之间的相关性。为一组中国患者计算基于HU的胸腰椎(T11和T12)截止阈值。
■对于骨质疏松症患者,胸腰段骨折的发生率明显高于其他部位。然而,目前大多数临床研究都集中在L1。
这项回顾性研究分析了2021年8月至2022年8月在我们医院接受胸部CT和DXA的患者。胸椎段HU值,腰椎T评分,计算髋部T评分进行比较,使用受试者工作特征曲线建立提示潜在骨密度异常的胸腰段HU阈值。
■总共,470名患者(72.4%为女性;平均年龄,65.5±12.3年)纳入本研究。DXA透露,在470名患者中,90(19%)患有骨质疏松症,180(38%)骨量减少,200(43%)的骨密度(BMD)正常。为了区分骨质疏松症和骨量减少,HU阈值确定为105.1(灵敏度,54.4%;特异性,T11和85.7的72.2%(灵敏度,69.4%;特异性,61.1%)为T12。为了区分骨量减少和正常骨密度,T11的HU阈值为146.7(灵敏度,57.5%;特异性,84.4%)和T12的135.7(灵敏度,59.5%;特异性,80%)。
■本研究支持胸部CT的HU值对BMD评估的意义。胸部CT为临床机会性筛查骨质疏松症提供了新的方法。当T11HU>146.7或T12HU>135.7时,除非检测到椎骨骨折,否则不需要额外的骨质疏松症测试。如果T11HU<105.1或T12HU<85.7,强烈建议进一步进行DXA测试。此外,椎体HU值比T11和L1椎体下降得更快,这可能解释了T12椎体骨折的高发生率.
METHODS: A retrospective study.
OBJECTIVE: To investigate the correlation between Hounsfield unit (HU) values measured by chest computed tomography (CT) and dual-energy Xray absorptiometry (DXA) T-scores. HU-based thoracolumbar (T11 and T12) cutoff thresholds were calculated for a cohort of Chinese patients.
BACKGROUND: For patients with osteoporosis, the incidence of fractures in the thoracolumbar segment is significantly higher than that in other sites. However, most current clinical studies have focused on L1.
METHODS: This retrospective study analyzed patients who underwent chest CT and DXA at our hospital between August 2021 and August 2022. Thoracic thoracolumbar segment HU values, lumbar T-scores, and hip T-scores were computed for comparison, and thoracic thoracolumbar segment HU thresholds suggestive of potential bone density abnormalities were established using receiver operating characteristic curves.
RESULTS: In total, 470 patients (72.4% women; mean age, 65.5±12.3 years) were included in this study. DXA revealed that of the 470 patients, 90 (19%) had osteoporosis, 180 (38%) had reduced osteopenia, and 200 (43%) had normal bone mineral density (BMD). To differentiate osteoporosis from osteopenia, the HU threshold was established as 105.1 (sensitivity, 54.4%; specificity, 72.2%) for T11 and 85.7 (sensitivity, 69.4%; specificity, 61.1%) for T12. To differentiate between osteopenia and normal BMD, the HU threshold was 146.7 for T11 (sensitivity, 57.5%; specificity, 84.4%) and 135.7 for T12 (sensitivity, 59.5%; specificity, 80%).
CONCLUSIONS: This study supports the significance of HU values from chest CT for BMD assessment. Chest CT provides a new method for clinical opportunistic screening of osteoporosis. When the T11 HU is >146.7 or the T12 HU is >135.7, additional osteoporosis testing is not needed unless a vertebral fracture is detected. If the T11 HU is <105.1 or the T12 HU is <85.7, further DXA testing is strongly advised. In addition, vertebral HU values that fall faster than those of the T11 and L1 vertebrae may explain the high incidence of T12 vertebral fractures.