The MDCT Morphological Features And Airway Abnormality In Smokers As Well As The Correlation With Pulmonary Function

Part ? Morphological and volumetric quantitative assessment of smokers by ulmonary MDCT scan and the correlation with pulmonary functional test ?Objective?To analyze the morphological features of smokers' lung under multi-detector computed tomography(MDCT)scan,then measure the CT volumetric parameters,and explore their correlation with pulmonary functional test(PFT)indexes.?Materials and Methods?Fifty-nine smokers were enrolled,with fourteen were fund with chronic obstructive pulmonary disease(COPD),and thirty-nine non-smokers were chosen as control group.All subjects underwent inspiratory and expiratory phase MDCT scan and PFT.The CT features were observed including centrilobular emphysema,paraseptal emphysema,bullae of lung,brochiectasis or bronchial wall thickness,parenchymal micronodules,ground glass opacity,mosaic attenuation,air trapping,interstitial lung disease,interlobular septal thickening and linear atelectasis.The CT quatitative parameters included the emphysema index of threshold of lung area with attenuation lower than-950 Housfield units(EI-950)and the mean lung density(MLD).Analyze the correlation between PFT indexes and pulmonary CT morphological features as well as volumetric parameters.?Results?1.Among three groups,significant difference was found in sex proportion,body mass index(BMI),PFT indexes including forced expiratory volume at 1 second(FEV1),forced vital capacity(FVC),the ratio of FEV1 and FVC(FEV1/FVC),the percentage of maximum expiratory flow rates at 50%(MEF50%(%P))as well as the percentage of the ratio of the diffusion capacity of the lung for carbon monoxide and alveolar volume(DLCO/VA(%P)),and emphysema index(EI),all with p value less than 0.01.2.There were also significant difference among three groups about the score and incidence of centrilobular emphysema,paraseptal emphysema and brochiectasis or bronchial wall thickness,with p value less than 0.01.3.In COPD patients,paraseptal emphysema and DLCO/VA(%P),brochiectasis r bronchial wall thickness and DLCO SB(%P)?DLCO/VA(%P),as well as EI and MEF25%(%P)?DLCO SB(%P)?DLCO/VA(%P)were all negatively related.In smokers with normal spirometry,there were negative correlation between centrilobular emphysema and FEV1/FVC?MEF25%(%P)?MEF50%(%P)?DLCO SB(%P)? DLCO/VA(%P),paraseptal emphysema and DLCO SB(%P)?DLCO/VA(%P),brochiectasis or bronchial wall thickness and DLCO/VA(%P),as well as EI and FEV1/FVC?MEF50%(%P),and MLD and FEV1(%P)?MEF25%(%P)were positively related.?Conclusion?MDCT can be used for evaluating smokers' pulmonary morphology,and the abnormal features and volumetric parameters can be used for predicting pulmonary functions.Part ? Analysis of small airway dimensions at inspiratory and expiratory phaseMDCT scan in smokers and the correlation with pulmonary function test ?Objective?Analyze the airway dimensions under multi-detector computed tomography(MDCT)scan at inspiratory and expiratory phase in smokers,and explore its correlation with pulmonary function test.?Materials and Methods?We enrolled 58 smokers,and 14 were found to be COPD patients by pulmonary function test(PFT),another 39 non-smokers and without COPD were chosen as control group.All 97 subjects underwent inspiratory and expiratory phase MDCT scan after PFT.Measure and calculate parameters including the airway dimensions: wall thickness(T),luminal area(LA)and wall area percentage(%WA),as well as the PFT indexes: forced expiratory volume at 1 second(FEV1),forced expiratory volume at 1 second%(FEV1%,%),the ratio of FEV1 and forced vital capacity(FEV1/FVC,%),and the ratio of the diffusion capacity of the lung for carbon monoxide and alveolar volume(DLCO/VA%).Analyze and compare the difference of airway dimensions and PFT indexes,and explore their correlation.?Results?1.Among three groups,Significant difference were found in airway dimensions including I-LA3~5,I-T6,I-%WA5 and E/I-LA3~6(p<0.05),and PFT parameters such as FEV1?FEV1/FVC and DLCO/VA%(p<0.05).2.There was negative correlation between I-T and DLCO/VA%,E/I-LA as well s FEV1/FVC,I-%WA6 ? FEV1/FVC in COPD patients,and the correlation coefficient between I-T and DLCO/VA% increased with the airways getting smaller from 3rd to 6th.I-LA4 and FEV1/FVC was positively correlated in COPD patients.3.In smokers without COPD,FEV1 and I-LA4,I-%WA4 as well as E/I-LA3,FEV1% and I-%WA6 ? DLCO/VA% and I-LA6 showed negative correlation,and the correlation coefficient of FEV1 with E/I-LA4 was greater than with E/I-LA3 and I-LA4.In non-smoker controls,there was negative correlation between I-T and DLCO/VA%,I-%WA4 and FEV1,E/I-L4 and FEV1.?Conclusion?Compared with PFT,MDCT scan,especially inspiratory and expiratory phase scan can evaluate small airways changes of smokers effectively,and detect the abnormal airways earlier.Part III Correlation between airway dimensions and emphysema as well as airtrapping indexes at inspiratory and expiratory phase MDCT scan in smokers ?Objective?Analyze the change of pulmonary airway dimensions,emphysema and air trapping indexs in long-term smokers without symptoms,under multi-detector computed tomography(MDCT)scan at inspiratory and expiratory phase.Explore the correlation between airway dimensions and emphysema as well as air trapping indexes.?Materials and Methods?32 smokers were served as smoking group,another 10 non-smokers were chosen as control group.All 42 subjects underwent inspiratory and expiratory phase MDCT scan.Using COPD software to automatically analyze the ratio of expiration/inspiration luminal area(LA-E/I)from the first to third airway,the emphysema index(EI),the ratio of expiration/inspiration mean lung density(E/IMLD)and the Relative Volume Change(RVC).Compare the difference of above parameters in the left,right and whole lung,between the smoking and control group.Using Pearson or Spearman algorithm to Analyze the correlation between airway dimensions and EI as well as air trapping indexes.?Results?1.All parameters including LA-E/I ?EI?E/IMLD and RVC in the left,right and whole lung were found no difference between the smoking and control group,with p value greater than 0.05.Compared with control group,the value of LA-E/I(first to third),VOL(E-I)were smaller,MLD(E/I)was larger in smokers.2.There were positive correlation between LA-E/I(first to third)and E/I MLD as well as RVC,which were more significant in the second and third airway than first airway.No correlation were found between the airway dimensions and EI in both groups.?Conclusion?Inspiratory and expiratory phase MDCT scan can assess the damage on airways and parenchyma caused by smoking effectively,and the air trapping indexes were more sensitive than emphysema indexes to airway change in smokers.