肺组织密度诊断结缔组织病继发间质性肺病的临床界值

Clinical optimal value of lung tissue density in diagnosis of interstitial lung disease secondary to connective tissue disease

目的探讨肺组织密度诊断结缔组织病(CTD)继发间质性肺疾病(ILD)的最佳界值。方法设置CTD未治疗组(50例)、CTD治疗组(50例)及健康对照组(20例)。在确诊当时、确诊后1年、2年、2.5年、3年时分别测定受试者的肺组织密度,并由专家组根据HRCT影像判断是否继发ILD。将健康者至确诊为CTD-ILD患者的最高肺组织密度均分为5个层次,计算每个层次上诊断CTD-ILD的真阳性及真阴性例数,利用诊断性ROC曲线求得敏感度及特异度的最佳界值。结果最终纳入统计的有43例患者,健康受试者的平均肺组织密度为-843.0 HU,确诊3年时测得患者最高的肺组织密度值为-672.6 HU,其他的界值为-800.4、-757.8及-715.2 HU,以HRCT为诊断CTD-ILD的金标准进行ROC曲线制作,根据约登指数计算出最佳界值为-779.1 HU,所对应的敏感度为0.838,而特异度为0.809。结论确诊CTD的部分患者有继发为ILD的倾向,肺组织密度的改变先于HRCT上异常表现,肺组织密度诊断CTD-ILD的最佳界值为-779.1 HU。

Objective To investigate the optimal value of lung tissue density in the diagnosis of(connective tissue disease)CTD(-interstitial lung disease)ILD. Methods This study included the CTD untreated group(50 cases), the CTD treatment group(50 cases) and the healthy control group(20 cases). At the time of diagnosis, one year, two years, two and a half years and three years after diagnosis, the lung tissue density of the subjects was measured, and the expert group judged whether there was any CTD-ILD imaging on HRCT. Lung tissue density from the healthy control group to subjects diagnosed with CTDILD was divided into five layers, and the true positive and true negative cases of CTD-ILD subjects were calculated, and then the optimal value of sensitivity and specificity was obtained by diagnostic ROC curve. Results Forty-threepatients’ clinicaldata were analyzed in this study. Average lungtissue density of healthy subjects was 843.0 HU.The highest density of lung tissue in patients diagnosed with CTD-ILD 3 years after diagnosis was-672.6 HU, and the other boundary value were-800.4 HU,-757.8 HU and-715.2 HU. HRCT performancewas thegolden standard in the diagnosis of CTD-ILD, and the ROC curve was made.The optimal cutoff value was-779.1 HU with a sensitivity of 0.838 and a specificity of 0.809 according to the Youden index. Conclusions In some patients with confirmed CTD, there was a tendency of being ILD.The change of lung tissue density was prior to HRCT imaging abnormality, and it showed that the optimal value of lung tissue density in the diagnosis of CTD-ILD was-779.1 HU.