胸椎QCT诊断骨质疏松BMD阈值的临床研究

The clinical study on diagnostic BMD thresholds of thoracic vertebral for osteoporosis

目的分析下部胸椎与腰椎骨密度的相关性并确定诊断骨质疏松及骨量减少的胸椎骨密度阈值。方法回顾性分析因临床需要进行腹部CT扫描的患者276名。测量T_(10)~L_(3)各椎体的BMD,使用Pearson相关分析各椎体间的BMD及胸椎(T_(10~12))与腰椎(L_(1)~L_(3))平均BMD的相关性,应用线性回归方程计算诊断骨质疏松及骨量减少的胸椎平均BMD阈值。结果T_(10)至L_(3)椎体BMD逐渐减低,BMD范围(120.49±35.96)mg/cm^(3)~(95.62±35.95)mg/cm^(3),T_(10)~L_(3)各椎体之间BMD均呈明显正相关(r=0.894~0.967,P<0.05),T_(10~12)平均BMD与L_(1~3)平均BMD相关系数为0.957。胸椎诊断骨质疏松及骨量减少的平均BMD阈值分别是96.59 mg/cm^(3)及134.75 mg/cm^(3)。结论胸椎与腰椎BMD呈明显相关性,胸椎BMD测量可以作为诊断骨质疏松及骨量减少的方法。

Objective To analyze the correlation between thoracic and lumbar bone mineral density and to identify specific diagnostic thresholds of osteoporosis and osteopenia for the thoracic spine.Methods Retrospective analysis of 276 patients who received abdomen non-contrast-enhanced CT scan for otherindication.BMD of each vertebra spanning T_(10)L_(3)was measured,the correlation between BMD of each vertebral body,mean T_(10)-T_(12)BMD and mean L_(1)-L_(3)BMD were analyzed using Pearson analysis.The cut-off values of thoracic spine(T_(10-12))averaged BMD for osteoporosis and osteopenia were calculated using linear regression.Results The BMD of vertebral body from T10 to L_(3)gradually decreased,with the highest BMD in the T10(120.49±35.96 mg/cm^(3))and lowest at L_(3)(95.62±35.95 mg/cm^(3)).Significant correlations in BMD among all measured thoracic and lumbar levels were observed(r=0.894-0.967,P<0.05),and a Pearson’s correlation coefficient between mean T_(10)-T_(12)BMD and mean L_(1)-L_(3)BMD was 0.957.Respective cut-off values of mean T_(10)-T_(12)BMD for osteoporosis and osteopenia was 96.59 mg/cm^(3)and 134.75 mg/cm^(3).Conclusion There is a high correlation between mean L_(1)-L_(3)BMD and mean T_(10)-T_(12)BMD,BMD measurement of thoracic spine can be used as a method for diagnosis of osteoporosis and osteopenia.