CT肺容积参数与肺功能、临床严重程度在结缔组织相关性肺间质病变分组中的相关性研究

Correlation Study Between CT Volume Parameters and Pulmonary Function and Clinical Severity in Patients with Connective Tissue-Associated Interstitial Lung Disease Grouping

目的探讨在结缔组织相关性肺间质病变(CTD-ILD)HRCT分组中患者的CT肺容积参数与肺功能、临床严重程度的相关性。方法搜集2013年9月至2016年9月在中南大学湘雅医院行HRCT证实的CTD-ILD患者191例,其中行肺功能检查43例。使用Volume定量分析软件,用肺密度阈值分割法测定43例患者感兴趣区的肺容积(VOI),共获得5个CT肺容积参数:全肺总容积(WL)、正常肺组织容积(NL)、间质纤维化肺容积(ILDV)、正常肺组织容积百分比(NL%)与间质纤维化肺容积百分比(ILDV%)。采用Camiciottoli视觉评分法对43例患者的HRCT图像肺纤维化水平进行评分。按GAP分级将43例患者的临床严重程度分为Ⅰ、Ⅱ、Ⅲ级。43例患者根据按HRCT表现分为寻常型间质性肺炎(UIP)组(26例)及非特异性间质性肺炎(NSIP)组(17例),观察两组中CT肺容积参数、视觉评分与肺功能、临床严重程度的相关性是否存在差异。结果 CTD-ILD患者的WL、NL与TLC、FVC、FEV1均呈中高度正相关,相关性不受CT表现分类的影响。CTD-ILD患者的NL%与FVC/预计值%均呈中高度相关,在UIP组相关性最高(r=0.93),稍高于整体及NSIP组,相关性不受CT表现分类的影响。CTD-ILD患者的ILDV%、ILDV、NL%与DLCO、DLCO/预计值%均呈中高度相关,其中ILDV%与DLCO/预计值%相关性最高,相关性不受CT表现分类的影响。NL%与DLCO/预计值%在NSIP组呈高度正相关(r值为0.91),相关性高于UIP组及整体。CTD-ILD患者的ILDV%、ILDV与GAP分级均呈中度正相关,NL%与GAP分级在UIP组(r=-0.89)及整体(r=-0.83)呈高度负相关,在NSIP组呈中度负相关。CT视觉评分与肺功能参数及GAP分级的相关性受CT表现分类的影响,CT视觉评分与DLCO、DLCO/预计值%在NSIP组和整体组均呈中度负相关,在UIP组无相关性,CT视觉评分与其它肺功能参数仍均无相关性。CT视觉评分与GAP分级在NSIP组呈中度正相关(r=0.64),在整体及UIP组无明显相关。结论 CT肺容积参数可用于评价CTD-ILD患者的肺功能、临床严重程度,但部分CT肺容积参数在CTD-ILD分组中评价肺功能、临床严重程度应相对谨慎。

Objective To analyze the correlation between CT lung volume parameters and pulmonary function and clinical severity in HRCT grouping of patients with connective tissue associated interstitial lung disease(CTD-ILD). Methods We retrospectively analyzed 191 patients with connective tissue disease who were confirmed interstitial lung disease by HRCT in Xiangya Hospital,Central South University from September 2013 to September 2016.Among them,43 patients underwent pulmonary function test. We used Volume quantitative analysis software to measure the lung volume of interest in 43 patients through density threshold segmentation and obtained five CT lung volume parameters:whole lung volume(WL),normally attenuated lung volume(NL),interstitial lung disease volume(ILDV),the percentage of normally attenuated lung volume(NL%) and the percentage of interstitial lung disease volume(ILDV%).The level of 43 patients’ pulmonary fibrosis were evaluated by Camiciottoli’s visual score. The clinical severity of 43 patients were divided into I,II and III grade according to GAP classification. We divided 43 patients into usual interstitial pneumonia(UIP) group(26 cases) and nonspecific interstitial pneumonia(NSIP) group(17 cases) by HRCT imaging and investigated whether there were differences in the correlation between CT classification,visual score and lung function parameters,clinical severity in two groups. Results WL and NL were moderately to highly positively correlated with TLC,FVC and FEV1 in patients with CTD-ILD,and the correlation was not affected by CT classification. The NL% was moderately to highly correlated with FVC/predicted value % in patients with CTD-ILD. The correlation in UIP group was the highest(r=0.93),followed by that in the whole group and NSIP group,and the correlation was not affected by CT classification. The ILDV%,ILDV and NL% were moderately to highly correlated with DLCO and DLCO/predicted value % in patients with CTD-ILD. The correlation between ILDV% and DLCO/predicted value % was the highest,and the correlation was not affected by CT classification.NL% was highly positively correlated with DLCO/predicted value % in NSIP group(r=0.91),and the correlation was higher than that in UIP group and the whole group. ILDV% and ILDV were moderately positively correlated with GAP score in patients with CTD-ILD.NL% was highly negatively correlated with GAP in UIP group(r=-0.89) and the whole group(r=-0.83)and moderately negatively correlated with GAP in NSIP group. The correlation between visual scores and pulmonary function parameters and grading of GAP was affected by CT classification. CT visual score was moderately negatively correlated with DLCO and DLCO/predicted value % in NSIP group and the whole group but not in UIP group. However,visual score has no correlation with any other pulmonary function parameters. CT visual score was moderately positively correlated with GAP score in NSIP group(r=0.64),but not in the whole group and UIP group. Conclusion CT lung volume parameters can be widely uesed in assessment of lung function and clinical severity in patients with CTD-ILD.However,we should be relatively cautious to evaluate lung function and clinical severity in CTD-ILD grouping when using some CT lung volume parameters.