Application Of Multislice Spiral CT Pulmonary Functional Imaging In The Evaluation Of Large Volume Lung Lavage For Pneumoconiosis

ObjectiveThe quantitative CT parameters of the two groups of pneumoconiosis patients before and after treatment were observed and compared with the results of routine pulmonary function test(PFT).Objective To evaluate the pulmonary function and efficacy of MSCT pulmonary function quantitative technique after pneumoconiosis lavage,and to analyze the correlation between quantitative CT and routine pulmonary function test(PFT).Materials and methods56 cases of pneumoconiosis diagnosed by Occupation disease prevention and treatment center were selected from October 2015 to August 2017,28 cases of pneumoconiosis who underwent Simultaneous large volume lung lavage with dual lung in hospital were selected as the observation group,Another 28 cases of pneumoconiosis,who received conservative treatment in the Department of Internal Medicine at the same time,were chosen as the control group.Before and after treatment,chest CT examination and pulmonary function test were performed,the parameters obtained by quantitative CT before and after treatment were compared between the two groups.Two kinds of breathing images obtained by MSCT were transmitted to Pulmo software for processing.The region-limited image segmentation technique was applied to automatically remove the trachea and bronchi,blood vessels,and surrounding bones,muscles and soft tissues.Some of the atmospheric tubes and blood vessels needed to be removed manually.Pulmo software was used to calculate lung density and lung volume including lung density at end deep inspiratory phase,lung density at end deep expiratory phase,mean lung density difference(MLDex-MLDin),lung volume at full inspiratory phase,lung volume at full expiratory phase,Lung volume difference(Yin-Vex),lung volume ratio(Vex/Vin).Clinical pulmonary function test parameters included Forced Expiratory Volume in First Second(FEV1),One Second Rate(FEV1/FVC),Forced Vital Capacity(FVC),Total Lung Capacity(TLC),Residual Volume(RV),forced expiratory volume in one second/forced vital capacity(RV/TLC).Independent sample t test was used to compare the differences between the observation group and the control group,and paired T test was used to observe the differences of the indexes before and after treatment in the same group.Pearson product error correlation analysis was used to examine the correlation between quantitative CT measurements and PFT indexes.ResultsAfter treatment,in the observation group the mean lung density at end deep expiratory phase(MLDex),mean lung density attend deep inspiratory phase(MLDin)were significantly lower than those before treatment(P<0.05).And the MLDex-MLDin,The end deep inspiratory volume(Vin),end deep expiratory volume(Vex),Vex-Vin were significantly higher than that before treatment(P<0.05).The degree of improvement in the observation group was significantly better than the control group(P<0.05).After treatment,the RV/TLC in the observation group were significantly lower than those before treatment(P<0.05);The forced vital capacity(FVC),forced expiratory volume in one second(FEV1),FEV1/FVC,residual volume(RV),total lung capacity(TLC)in the observation group were significantly higher than those before treatment(P<0.05),and the degree of improvement after treatment in the observation group was significantly better than the control group(P<0.05).The analysis showed that lung density index MLDex-MLDin had the positive corrections with pulmonary function index FEV1,FVC and FEV1/FVC(r=0.883,0.875,0.856,P<0.05).The lung volume index Vex/Vin had a positive correlation with pulmonary function index RV/TLC(r=0.897,P<0.05),and the Vin-Vex had a positive correlation with FVC(r=0.911,P<0.05).ConclusionThe pulmonary volume and density were measured by MSCT pulmonary function quantitative technique before and after treatment showed that the lung density and volume index were improved after lung lavage.It was valuable in evaluating the short-term efficacy of whole lung lavage with high volume lung lavage in the treatment of pneumoconiosis.It has a certain correlation with the pulmonary function indexes obtained by PFT.