定量CT测量T12骨密度替代病变腰椎用于骨质疏松诊断的可行性

Feasibility of bone mineral density of T12 measured with quantitative CT for replacing abnormal lumbar vertebrae for diagnosis of osteoporosis

目的探讨在低剂量CT肺癌筛查联合定量CT骨密度检查中,以测量T12椎体骨密度替代病变的L1或L2用于骨质疏松诊断的可行性。方法选取1 298名接受低剂量CT肺癌筛查联合定量CT骨密度检查的健康体检者,测量其T12、L1、L2椎体骨密度,并计算校准的T12骨密度,记为T12^*。以L1+L2为诊断标准,分别分析各椎体组合T12+L1、 T12+L2、 T12^*+L1、T12^*+L2与L1+L2评估骨量的一致性和诊断骨质疏松的差异性。结果各椎体组合与L1+L2评估骨量的一致性均较好(Kappa 均>0.75,P均<0.05)。各椎体组合诊断骨质疏松的特异度均>98%。T12+L1、 T12+L2 诊断骨质疏松的敏感度分别为73.33%(143/195)及77.95%(152/195);而T12^*+L1、T12^*+L2诊断骨质疏松的敏感度分别为83.08%(162/195)及90.26%(176/195)。结论定量CT测量T12骨密度替代病变L1或L2,可能降低诊断骨质疏松的敏感度,应对其进行校准。

Objective To explore the feasibility of bone mineral density (BMD) of T12 for replacing abnormal L1 or L2 for diagnosis of osteoporosis during lung cancer screening with low-dose CT and bone mineral density examination with quantitative CT.Methods Totally 1 298 healthy individuals who underwent lung cancer screening with low-dose CT and BMD examination with quantitative CT were enrolled.BMD of T12 to L2 vertebrae were measured,and the calibrated BMD of T12 was calculated and recorded as T12^*.Taking L1+L2 as diagnostic criteria,the consistencies in bone mass assessment and the differences in diagnosis of osteoporosis among vertebral combinations of T12+L1,T12+L2,T12^*+L1,T12^*+L2 and L1+L2 were analyzed,respectively.Results There were good consistencies between vertebral combinations and L1+L2 in bone mass assessment (all Kappa >0.75,all P<0.05).The specificities of vertebral combinations in osteoporosis diagnosis were all >98%.The sensitivities of T12+L1 and T12+L2 in osteoporosis diagnosis were 73.33%(143/195) and 77.95%(152/195),respectively,whereas of T12^*+L1 and T12^*+L2 in osteoporosis diagnosis were 83.08%(162/195) and 90.26%(176/195),respectively.Conclusion BMD of T12 for replacing abnormal L1 or L2 during quantitative CT can reduce the sensitivity in diagnosis of osteoporosis,therefore BMD of T12 should be calibrated in measurement.