Value Analysis of CT Lung Volume Parameters in Evaluating Pulmonary Function and Severity of CTD-ILD

ZHANG Yanni; XU Zhifu

doi:10.3969/j.issn.1002-3429.2024.03.015

Abstract：Objective To analyze the value of CT lung volume parameters in evaluating pulmonary function and se-verity of connective tissue disease-associated interstitial lung disease(CTD-ILD).Methods A total of 126 patients with CTD-ILD treated from April 2020 to December 2022 were selected and divided into grade Ⅰ group(n =43),grade Ⅱ group(n =45)and grade Ⅲ group(n =38)according to the clinical severity of CTD-ILD.All patients received pulmonary function tests.CT lung volume parameters[normal lung volume(NL),interstitial lung disease volume(ILDV),whole lung volume(WLV),percentage of normal lung volume(NL％),percentage of interstitial lung disease volume(ILDV％)]were ob-tained by high-resolution CT examination.The pulmonary function indexes[total lung capacity(TLC),forced expiratory vol-ume in the first second(FEV1),forced vital capacity(FVC),residual volume(RV),forced expiratory volume in the first second to the estimated value(FEV1％)],GAP grade score,image fibrosis score and CT lung volume parameters were com-pared among the groups.The relationship between CT lung volume parameters and pulmonary function index,GAP grade score and image fibrosis score was analyzed,and diagnosis of CTD-ILD severity grade Ⅲ was performed using CT lung volume pa-rameters.The diagnostic efficacy of CT lung volume parameters combined with pulmonary function index in CTD-ILD severity grade Ⅲ was analyzed.Results FVC,FEV1,TLC,RV,and FEV1％were the highest in grade Ⅰ group,followed by grade Ⅱ group and grade Ⅲ group,while GAP grade score and international fibrosis score were the lowest in grade Ⅰ group,fol-lowed by grade Ⅱ group and grade Ⅲ group(P<0.05).NL,WL,and NL％were the highest in grade Ⅰ group,followed by grade Ⅱ group and grade Ⅲ group,while ILDV and ILDV％were the lowest in grade Ⅰgroup,followed by grade Ⅱ group and grade Ⅲ group(P<0.05).NL,WL,and NL％were positively correlated with FVC,FEV1,TLC,RV,and FEV1％,and negatively correlated with GAP grade score and image fibrosis score(P<0.05).ILDV and ILDV％were positively corre-lated with GAP grade score and image fibrosis score,but negatively correlated with FVC,FEV1,TLC,RV and FEV1％(P<0.05).The area under the curve(AUC)of NL,WL,ILDV,NL％and ILDV％in the diagnosis of CTD-ILD severity grade Ⅲ was 0.765,0.715,0.754,0.789 and 0.768,respectively.The AUC of NL,WL,ILDV,NL％and ILDV％in combina-tion for diagnosis was the largest(0.944).Conclusion NL,WL,ILDV,NL％and ILDV％are closely related to pulmona-ry function in CTD-ILD patients,and combined detection has high diagnostic efficacy for the severity of the disease.