Study On The Relationship Between CT Quantitative Assessment And Pulmonary Function In Chronic Obstructive Pulmonary Disease Based On COPD Semi-automatic Analysis Software

Partl Correlation between CT quantitative measurement indexes andpulmonary function,clinical indices in COPD patientsObjectiveTo explore the correlation between CT quantitative measurement parameters and physiological measurement,clinical indices of the chronic obstructive pulmonary disease by semi-automatic analysis software(Philips Healthcare).Materials and MethodsThere were 60 patients diagnosed with COPD and 15 normal groups by pulmonary function tests(PFT)who underwent multislice spiral CT scans on chest both at end-inspiratory and end-expiratory were proceeded 3 days later after PFT and CAT questionnaire.Using COPD Analysis software(Philips Healthcare),a three-dimension quantitative measurement was employed to assess the CT parameters of emphysema,air trapping and airway.Airway measurement was provided average values along centerline between start and end postion in the bronchiole of right upper apica lobes by software.?parameters of emphysema(LAA%)(end-inspiratory,filter B);air trapping(end-inspiratory/end-expiratory,filter B),which included relative volume change(RVC)-860?950,the expiration to inspiration ratio of mean lung density(MLDE/I);?parameters of airway were measured(end-inspiratory,filter D),which included the following parameters:wall thickness(WT),lumen diameter(LD),Pi10,wall area(WA),,wall area ratio(WA%),lumen area ratio(Ai%),WA/LA.The indexes were compared in pairs respectively.Spearman rank correlation test and multiple variable analysis were used to evaluate the relationship between the above quantitative CT parameters and PFT,clinical indexes.Results1.The correlation between the CT parameters of airway(WT,Pi10,T/PA,WA,WA%,Ai%,WA/LA)and airflow limitation(r=-0.33?-0.63,r=-0.38?0.29,<0.05),diffusing capacity(r=-0.33?-0.48,<0.05),airway resistance(r=-0.23?-0.53,r=0.29-0.61,<0.05)also was significative(r2<0.5,P<0.05),and the relative value of the parameters(WA%,Ai%,WA/LA)is more useful than the absolute value(WT,Pi 10,T/PA,WA).2.The correlation between the CT parameters of emphysema(LAA%),air trapping(RVC-860?-950,MLDE/I)and airflow limitation(r= =0.86,-0.87;r=-0.86?-0.90,<0.001),diffusing capacity(r=-0.82;r=-0.83,-0.80,<0.001),airway resistance(X5,r=-0.78;r=-0.77,-0.74;Z5,R5;R20,Fres,r=0.71-0.84,<0.001)was statistic significative(r2>0.5,P<0.001).3.Among the clinical indexes,there were different in age,CAT scores and smoking index,which were increased with the severity of illness.Besides,BMI was not different.ConclusionThe correlation between quantitative CT measurement parameters and lung function has statistical significance,in which the CT parameters of emphysema and air trapping are better correlated with lung function,and are more valuable for assessment of emphysema.Part2:Influence of the spatial distribution of emphysema on pulmonary function and clinical severity in chronic obstructive pulmonary disease patients ObjectiveTo investigate the impact of the spatial distribution of emphysema on the pulmonary function and clinical severity in patients with COPD by semi-automatic analysis software(Philips Healthcare).Materials and methods84 cases COPD patients were underwent chest MSCT scans(end-inspiration).For the quantitative assessment,percentage of low attenuation areas(threshold value?-950HU)were automatically calculated for each lobe by the post processing software(Philips Healthcare).?The Spearman rank test was used to assess the correlation between LAA%and the pulmonary function(FEV1,FEV1/FVC,Fres,DLcoSB%).? According to the heterogeneity index HI[HI=(%LAAupper-%LAAlower)/(%LAAupper+%LAAlower)],emphysema was divided into different types(LAA%?1%no-emphysema groups,LAA%>1%and HI>0%:predominantly upper-lobe subgroup;LAA%>1%and HI<0%predominantly lower-lobe subgroup);and the relationship between the 2 subgroups in the emphysema group and clinical stage was analyzed by chi-square test,and the difference of lung function between groups was analyzed by t-test.Results1.LAA%in upper lobes and lower lobes were significiant correlated with lung function(P<0.05),and the correlation coefficient absolute value with FEV1,FEV1/FVC(rs=-0.69,-0.65)is higher in both lower lobes,while with DLcoSB%(rs=-0.65)is higher in both upper lobes.2.The difference of pulmonary function(FEV1,FEV1/FVC,Fres,DLcoSB%)between no-emphysema group and emphysema group was statistically significant(P<0.05).The difference of FEV1,FEV1/FVC and clinical severity in the 2 subgroup was statistically significant(P<0.05),Fres and DLcoSB%were just the opposite.ConclusionThe spatial distribution of emphysema in chronic obstructive pulmonary disease reflects the pulmonary function and the severity of the disease.