Clinical Characteristics Analysis Of Patients With Chronic Obstructive Pulmonary Disease Based On Pulmonary Quantitative CT

[Objective]To explore the clinical characteristics of patients with chronic obstructive pulmonary disease(COPD)based on quantitative CT measurement indicators of the lungs,and analyze the correlation between quantitative CT measurement indicators of the lungs and lung function,acute exacerbation,and respiratory symptoms.[Methods]This cross-sectional study included 186 patients with stable COPD who visited the respiratory clinic of Beijing Hospital from March 2021 to February 2022.Demographic,clinical manifestations,lung function,and high-resolution CT(HRCT)data were collected.HRCT raw DICOM data were processed using the Shenzhou Dexin FACT medical imaging information system,and the emphysema index pixel index-950(PI-950)and the 6th generation bronchial airway wall thickness(6T)and 6th generation bronchial airway wall area percentage(6WA%)which represent segmental and subsegmental bronchi were automatically measured.The study subjects were divided into two groups based on PI-950:high and low emphysema,and the clinical characteristics of the two groups were analyzed.Use Spearman’s correlation or Pearson correlation to determine the correlation between PI-950,6T,6WA%and lung function indicators.Based on the past year’s acute exacerbation,binary grouping(non frequent acute plus recombination and frequent acute plus recombination)was used as the dependent variable,and multivariate logistic regression analysis was conducted to investigate the correlation between PI-950,6T,6WA%and acute exacerbation.PI-950 and 6T were combined with clinical manifestations and lung function to establish relevant models for acute exacerbation of COPD.The ROC curve was used to evaluate and compare the value of different models.According to the Modified British medical research council dyspnea scale(mMRC)score(0-1 points for low group,2-4 points for high group)and wheezing(non wheezing group and wheezing group),the research objects were respectively divided into two groups as dependent variables.Multivariate logistic regression analysis was conducted to investigate the correlation between PI-950,6T,6WA%and the above clinical manifestations.[Results]Among 186 patients,162 were males(87.1%)and 24 were females(12.9%).They aged 68.9±9.3 years old.The study subjects were divided into two groups based on the median PI-950(2.3%),with those with a score greater than 2.3%classified as high emphysema(84 cases)and those with a score less than or equal to 2.3%classified as low emphysema(85 cases).The proportion of males and patients with a history of smoking,smoking index,mMRC score,COPD assessment score(CAT),number of severe acute exacerbations in the past year,proportion of triple therapy,and double bronchiectasis therapy in the high emphysema group were higher than those in the low emphysema group,while body mass index(BMI),proportion of non medication,and inhaled corticosteroids(ICS)/long-acting beta-agonists(LABA)were lower than those in the low emphysema group(all P<0.05).The FVC%pred,FEV1%pred,FEV1/FVC,DLCO%pred,and MMEF%pred after medication in the high emphysema group were lower than those in the low emphysema group(all P<0.05).The 6T,6th generation bronchial airway outer diameter(6Do),6th generation bronchial airway inner diameter(6Di),6th generation bronchial airway wall area(6WA),6th generation bronchial airway total area(6Ao),and 6th generation bronchial airway inner area(6Ai)of the high emphysema group were all higher than those of the low emphysema group,while the 6th generation bronchial airway wall thickness percentage(6T%)and 6WA%were lower than those of the low emphysema group(all P<0.05).There was no statistically significant difference in other indicators between the groups(all P>0.05).PI-950 is related to the percentage of first second forced expiratory volume(FEV1)to expected value(%pred)after medication,FEV1/forced vital capacity(FVC)after medication,carbon monoxide diffusion to expected value(DLCO%pred),and maximum mid expiratory flow rate to expected value(MMEF%pred)after medication(all P<0.05).6T is associated with FEVi/FVC after medication,DLCO%pred and MMEF%pred after medication(all P<0.05).6WA%is correlated with DLCO%pred(P<0.05).There were 45 cases(24.2%)in COPD frequent acute exacerbation group,while 141 cases(75.8%)in non frequent acute exacerbation group.The median PI-950 was 4.2%in the frequent acute exacerbation group and 1.5%in the non frequent acute exacerbation group.The frequent acute exacerbation group was significantly higher than the non frequent acute exacerbation group(P<0.05).The median of 6T(after BSA square root correction)was 0.950mm for the frequent acute exacerbation group and 0.927mm for the non frequent acute exacerbation group.The frequent acute exacerbation group was significantly higher than the non frequent acute exacerbation group(P<0.05).Multivariate logistic regression model analysis showed that after adjusting for demographic,smoking,comorbidities,and pulmonary function confounding factors,the likelihood of frequent acute exacerbation increased by 2.920 times for every 0.1mm increase in 6T(OR=3.920,95%CI:1.411-10.889).6T,PI-950,and 6T combined with PI-950 were used to establish correlation models with frequent acute exacerbation of COPD,the area under curve(AUC)was 0.824,0.787,and 0.822,respectively.The final correlation model of COPD frequent acute exacerbation was selected based on the combination of 6T,PI-950,clinical manifestations,and lung function,which AUC was 0.826,with sensitivity of 80.6%and specificity of 77.3%.There were 83 cases(44.6%)in the high group of mMRC,and 65 cases(34.9%)in the wheezing group.The median PI-950 was 5.1%in the mMRC high group and 1.5%in the low group.PI-950 of the high group was significantly higher than the low group(P<0.05).The average value of 6WA%was 71.5%±2.6%in the wheezing group,and 70.5%±2.8%in the non wheezing group.6WA%of the wheezing group was higher than the non wheezing group(P<0.05).Multivariate logistic regression model analysis showed that after adjusting for demographic,smoking,comorbidities,and pulmonary function confounding factors,for every 10%increase in PI-950,the risk of mMRC elevation increased by 67.3%(OR=1.673,95%CI:1.052-2.658),and for every 10%increase in 6 WA%,the risk of wheezing increased by 3.189 times(OR=4.18,95%CI:1.070-16.395).[Conclusion]1、COPD patients with significant imaging emphysema are more exposed to smoking,with more severe clinical symptoms,poorer lung function,and a higher frequency of acute exacerbation.2、Airway wall thickening in patients with COPD is associated with frequent acute exacerbation,and the establishment of an acute exacerbation related model based on the combination of proximal airway wall thickness,clinical manifestations,and lung function in patients with COPD is valuable;3、Pulmonary quantitative CT is valuable in clinical evaluation of patients with COPD and is a beneficial supplement to lung function.