Study On The Correlation Between Lung CT Quantitative Evaluation And Pulmonary Function In Patients With COPD Based On 3D Slicer

ObjectiveBy observing the correlation between quantitative volume evaluation index of lung CT and pulmonary function in patients with chronic obstructive pulmonary disease（COPD）,the value of quantitative index of lung CT in the evaluation of COPD patients was discussed.MethodsA total of 161 admitted patients with chronic respiratory symptoms were admitted to the Respiratory Department of the First Affiliated Hospital of Jinzhou Medical University from January 2021 to January 2023.All patients were required to complete pulmonary function examinations and lung deep inspiration phase CT scans.The CT scanner is a 128-layer high-resolution CT（SIEMENS Healthcare,Germany）,with a scanning layer thickness of 0.625 mm and a reconstruction layer thickness of 1.0 mm.The open-source software 3D Slicer（version 5.0.3）platform is used to quantitatively evaluate lung CT using Lung Analyzer software.The analysis parameters are: total lung volume,emphysema volume,infiltrating volume,and collapsed volume,the calculation parameters are: the percentage of emphysema volume in total lung volume（TE%）,the percentage of lung infiltration volume in total lung volume（TI%）,and the percentage of lung collapse volume in total lung volume（TE%）.The pulmonary respiratory function tester is Care Fusion pulmonary function tester（Shanghai）.The analysis parameters are: forced expiratory volume in the first second（FEV₁）,forced vital capacity（FVC）,maximum mid-expiratory flow rate（MMEF）.The calculation parameters include: the percentage of forced expiratory volume in the first second after the maximum deep breath（FEV₁/FVC%）,the percentage of forced expiratory volume in the first second（FEV₁% pred）The percentage of the measured value of the maximum expiratory middle flow rate to the predicted value（MMEF75/25 %pred）.Calculate the correlation between CT quantitative measurement indexes and lung function indicators.ResultsThe quantitative volume evaluation indexes of lung CT have significant correlation with lung function indexes,among which the proportion of emphysema（TE%）has strong negative correlation with lung function indexes FEV₁/FVC%,FEV₁% pred,MMEF75/25% pred,with correlation coefficients of-0.650,-0.506 and-0.537 respectively;There was a significant positive correlation between the proportion of lung infiltration（TI%）and FEV₁/FVC%,FEV₁% pred,and MMEF75/25% pred,with correlation coefficients of 0.511,0.297,and 0.369,respectively;The proportion of lung collapse（TC%）was positively correlated with FEV₁/FVC%,FEV₁% pred,and MMEF75/25% pred,with correlation coefficients of 0.487,0.258,and 0.340,respectively;Among them,the predictive ROC curve AUC of TE% for diagnosing COPD is 0.785,the optimal cutoff value is 15.300,the sensitivity is 0.729,and the specificity is 0.767;In the control group,TI%,TC% and FEV₁/FVC% were significantly correlated,with correlation coefficients of 0.491 and 0.444 respectively.In patients with chronic obstructive pulmonary disease,TE% and FEV₁/FVC%,FEV₁% pred,MMEF75/25% pred were significantly correlated,with correlation coefficients of-0.607,-0.476 and-0.436 respectively.At the same time,TI%,TC% and FEV₁/FVC% were significantly correlated,with correlation coefficients of 0.391 and 0.402 respectively;In the GOLD Ⅰ and Ⅱ groups of COPD patients,TE% has a significant negative correlation with FEV₁/FVC%,with a correlation coefficient of-0.312.In the GOLD Ⅲ and Ⅳ groups,TE% has a significant negative correlation with FEV₁/FVC%,with a correlation coefficient of-0.679.At the same time,TE% has a significant negative correlation with FEV₁% pred and MMEF75/25% pred,with a correlation coefficient of-0.530 and-0.423,respectively,with moderate intensity.P<0.05,the difference was statistically significant.Conclusions1.In patients with chronic obstructive pulmonary disease,the quantitative evaluation indexes of lung CT,emphysema volume（TE%）,lung infiltration volume（TI%）,and lung insufficiency volume（TC%）,have good correlation with the lung function indexes FEV₁/FVC%,FEV₁% pred,and MMEF75/25% pred,suggesting that the quantitative evaluation indexes of lung CT,especially TE%,have certain value for the evaluation of the condition of COPD patients.2.The correlation between（TE%）,the quantitative evaluation index of lung CT,and the lung function of patients with severe and extremely severe chronic obstructive pulmonary disease is stronger than that of patients with mild and moderate chronic obstructive pulmonary disease.It is suggested that TE% is more sensitive to the evaluation of COPD patients with severe disease.