Clinical Analysis Of Respiratory Biphasic CT Parameter Response Maping In The Evaluation Of The Severity Of COPD

Objective:To analyze the quantitative index of the parametric response maping（PRM）in the assessment of the severity of chronic obstructive pulmonary disease（COPD）by grouping the risk degree of COPD.To explore the differences in basic clinical data,lung function,PRM and comprehensive assessment among patients with different disease risk levels,and to provide research methods for early detection,diagnosis,evaluation and treatment of the disease.Methods:A total of 81 patients with stable chronic obstructive pulmonary disease who met the inclusion criteria in the outpatient Department of Respiratory and Critical Care Medicine of the First Hospital of Hohhot from September 2021 to September 2022 were enrolled.Pulmonary function test and pulmonary respiratory dual-phase CT scan were performed to obtain image data imported into the processing software.PRM parameters(PRM^Normal,PRM^Emph,PRM^{f SAD})were generated and divided into low risk group and high risk group according to the percentage of forced expiratory volume in 1 second predicted value（FEV₁%Pred）.The basic clinical data（age,gender,height,weight,BMI,smoking index,GOLD classification）,PRM parameters,pulmonary function indexes（FEV₁,FVC,FEV₁/FVC,FEV₁%pred）of the two groups were analyzed.The comprehensive assessment indicators（CAT score,m MRC score,6MWD,BODE index,risk of acute exacerbation）were different.Statistical methods were used to draw scatter plots and calculate correlation coefficients,and the correlation between PRM parameters and pulmonary function indicators and comprehensive assessment indicators was analyzed.Results:（1）According to FEV1%Pred,81 subjects were divided into two groups.There were 46 cases in the low-risk group,29 males and 17 females,with an average age of72.11±8.580 years,12 cases of GOLD gradeⅠand 34 cases of GOLD gradeⅡ.There were35 cases in the high-risk group,including 32 males and 3 females,with an average age of67.54±8.469,26 cases of GOLD gradeⅢand 9 cases of GOLD gradeⅣ.There were significant differences in age（P=0.019<0.05）and gender（P=0.003<0.05）between the two groups.The patients in the high-risk group were mainly elderly men with younger age.There were no significant differences in height,weight,BMI and smoking index between the two groups（P>0.05）.（2）The mean of PRM^Normalparameters of respiratory biphasic CT in the low-risk group was higher than that in the high-risk group,and the difference was statistically significant（0.5119±0.0732vs0.3635±0.0545,p<0.05）.The mean of PRM^Emphand PRM^{f SAD}parameters in the low-risk group were lower than those in the high-risk group.The difference wasstatistically significant（0.1494±0.0408vs0.2263±0.0333,0.2500±0.0550vs0.3668±0.0250,p<0.05）.（3）The mean or median（interquartile range）of FEV₁,FEV₁/FVC,FVC and FEV₁%pred in the low risk group were greater than those in the high risk group.The differences were statistically significant（1.535±0.475vs0.886±0.233,0.561±0.079vs0.438±0.053,2.510（0.920）vs2.000（0.640）,0.682（0.217）vs0.356（0.315）;p<0.05）.（4）The mean or median（interquartile range）of CAT score,m MRC score,BODE index and the risk of acute exacerbation in the low-risk group were lower than those in the high-risk group.The differences were statistically significant（8.13±3.600vs017.54±5.807,1（1）vs2（1）,1（2）vs4（2）,1（1）vs3（2）,p<0.05）.The median（interquartile range）of 6MWD in the low-risk group was significantly higher than that in the high-risk group（423（44）vs366（101）,p<0.05）.（5）The PRM^Normalparameters of respiratory dual-phase CT were positively correlated with FEV₁,FVC,FEV_1/FVC,FEV₁%pred（r=0.794,0.644,0.667,0.769,P<0.05）.PRM^Emphwas negatively correlated with FEV₁,FVC,FEV₁/FVC and FEV₁%pred（r=-0.763,-0.612,-0.658,-0.745,P<0.05）.PRM^{f SAD}was negatively correlated with FEV₁,FVC,FEV₁/FVC,FEV₁%pred（r=-0.797,-0.616,-0.688,-0.779,P<0.05）,and PRM parameters were significantly correlated with pulmonary function indexes.（6）The PRM^Normalparameters of respiratory biphasic CT were negatively correlated with CAT score,m MRC score,BODE index and the risk of acute exacerbation（r=-0.782,-0.725,-0.784,-0.742,P<0.05）,and positively correlated with 6MWD（r=0.800,P<0.05）.P<0.05).PRM^Emphwas positively correlated with CAT score,m MRC score,BODE index and risk of acute exacerbation（r=0.781,0.694,0.757,0.710,P<0.05）,and negatively correlated with 6MWD（r=-0.727,P<0.05）.PRM^{f SAD}was positively correlated with CAT score,m MRC score,BODE index and risk of acute exacerbation（r=0.755,0.674,0.789,0.769,P<0.05）,and negatively correlated with 6MWD（r=-0.730,P<0.05）.PRM parameters were significantly correlated with comprehensive assessment indicators.Conclusion:（1）COPD mainly occurred in the elderly,and the high-risk group tended to be younger elderly.Male was the dominant population of COPD,especially in the high-risk group.（2）PRM^{f SAD}and PRM^Emphof respiratory biphasic CT are two important structural changes in COPD,and PRM^Normalis a quantitative parameter of normal lung tissue.In the assessment of the severity of COPD,PRMf SAD and PRMEmph increase when the risk of COPD increases.PRM^Normaldecreased,consistent with the progression of the disease.（3）The parameters PRM^{f SAD},PRM^Emph,PRM^Normalof respiratory dual-phase CT are significantly correlated with pulmonary function indexes and comprehensive evaluation indexes.It is an important cutting-edge technology for the evaluation of the severity of COPD and an important research method for the early detection,diagnosis and treatment of COPD.