Quantitative Study Of COPD Based On CT Double-phase Scanning

ObjectiveThis research contains two parts.1.To investigate the clinical value of CT quantitative scanning in the diagnosis of COPD based on double meteorological CT quantitative analysis.2.Double meteorological CT quantitative measurement index and PFT correlationstudy of COPD to investigate the diagnostic value of CT pulmonary function in COPD.Part one1.Materials and methodswe collected double meteorological chest CT scan data of normal medical examination population and COPD patients in our hospital from October 2016 to January2018.Double meteorological scan was signed and scanned after patients'Informed consent.Inclusion criteria:(1)normal physical examination in our hospital,without any chest symptoms and chest CT scan is normal;(2)routine examination of pulmonary function shows FEV1/FVC<0.70 after the inhalation of bronchodilator;(3)both inspiratory and expiratory images were complete.(4)the fissures of the lung on CT images are clear;Transmit the inspiratory and expiratory CT images into the FACT-Digital lung ~TMM data analysis platform to analysis double meteorological scan data;Using SPSS20.0 statistical analysis software,the measurement data was represented by±s;(1)Respectively,the normal subjects and the COPD group were aspirated phase and expiratory phase CT quantitative indicators:lung volume,average lung density and emphysema index paired sample t test.The difference was significant(p<0.05).(2)Double meteorological quantitative indexes of CT in normal group and COPD group,pulmonary volume,mean lung density and emphysema index were tested by independent samples t-test.The difference was significant(p<0.05).(3)Whole lung and left and right lung volume difference,volume ratio,average lung density difference,density ratio in normal group and COPD group were tested by independent samples t-test.The difference was significant(p<0.05).2.Resultsa total of 92 normal and 62 COPD subjects were eventually included.1.There were significant difference of the whole lung,right lung and left lung volume,average lung density,EI between normal and COPD patients in spiratory phase compared with exhalation.p<0.001,LVin>LVex,MLDin<MLDex.No matter in normal and COPD patients,the volume of the right lung is larger than the volume of the left lung,and there is no difference in the left and right lung density(p=0.867,p=0.166,p=0.865,p=0.402).2.There were significant difference of the whole lung,right lung and left lung volume,average lung density,EI in normal compared COPD patients,p<0.001.The whole lung,right lung and left lung LV,EI of COPD patients were significantly greater than normal,the MLD less than normal.3.There were no significant difference in LVin-LVex between COPD and normal subjects,p=0.611.Right lung LVin-LVex difference was not statistically significant,p=0.718.Left lung LVin-LVex difference was not statistically significant,p=0.373.4.There were significant difference of the total lung,right lung and left lung LVex/in?MLDex-MLDin?MLDex/in in normal compared COPD patients,p<0.001.The whole lung,right lung and left lung LVex/in?MLDex/in of COPD patients were significantly greater than normal,the MLDex-MLDin less than normal.3.summary1.There were statistically significant differences in quantitative indices of biphasic CT between normal and COPD patients.It can reflect the pathophysiology of the patient's lungs.Normal and COPD patients LVex<LVin,MLDex>MLDin,EIex>EIin.COPD patients are greater than normal in LV,EI.COPD patients are less than normal in MLD.2.Biphasic CT quantification indicators MLDex/in,MLDex-MLDin,LVex/in have good reference value and clinical significance in judging lung tissue gas retention and ventilatory dysfunction.Part two1.Materials and methodswe collected double meteorological chest CT scan data of COPD patients in our hospital from October 2016 to January 2018.Double meteorological scan was signed and scanned after patients'Informed consent.Inclusioncriteria:(1)routineexaminationofpulmonaryfunctionshows FEV1/FVC<0.70 after the inhalation of bronchodilator;(2)both inspiratory and expiratory images were complete.(3)the fissures of the lung on CT images are clear;Exclusion criteria was the same as the first part.Using SPSS20.0 statistical analysis software,the measurement data was represented by±s;The normality test was performed by Shapiro-Wilk test(W test)andthe test level was?=0.05;Normal subjects and GOLD grades were compared using the Cruskal-Wallis rank sum test,the test level was?=0.05;Pearson correlation analysis or Spearman rank correlation analysis were used to test the correlations between the quantitative measurements of CT and pulmonary function,the test level was?=0.05.Useing SPSS to plot scatter plots and Prism 6software was used to draw the required bar graphs.2.ResultsPart two:a total of 58 COPD subjects were eventually included.1.With the increase of GOLD level,LVin,emphysema,EI?LVex/in?MLDex/in gradually increased,MLDin changed insignificantly,MLDex,MLDex-MLDin and LVin-LVex gradually decreased.2.LVin was negatively correlated with FEV1%(r=-0.270,p<0.05).LVin was positively correlated with FVC and TLC(r=0.412,r=0.549,p<0.01).LVex and FVC were not statistically significant,p>0.05.LVex was negatively correlated with FEV1%and FEV1/FVC%(r=-0.561,r=-0.619,p<0.01).LVex was positively correlated with RV and RV%/TLC(r=0.474,r=0.285,p<0.01).3.MLDin was positively correlated with FEV1%and FEV1/FVC%(r=0.375,r=0.472,p<0.01).MLDin was negatively correlated with RV(r=-0.360,p<0.05).MLDex was positively correlated with FVC,FEV1%and FEV1/FVC%(r=0.463,r=0.741,r=0.711 p<0.01).MLDex was negatively correlated with RV and RC%/TLC(r=-0.525,r=-0.531,p<0.01).4.EIin was negatively correlated with FEV1%,FEV1/FVC%,DLCO and DLCO/VA(r=-0.543,r=-0.583,r=-0.542,r=-0.706,p<0.01).EIex was negatively correlated with FEV1%,FEV1/FVC%,DLCO and DLCO/VA(r=-0.693,r=-0.698,r=-0.629,r=-0.619,p<0.01).5.LVin-LVex was positively correlated with FVC,FEV1%,FEV1/FVC%,DLCO and TLC(r=0.790,r=0.557,r=0.410,r=0.375,r=0.502,p<0.01).LVin-LVex was negatively correlated with RV%/TLC(r=-0.587,p<0.01).6.LVex/in was negatively correlated with FVC,FEV1%and FEV1/FVC%(r=-0.652,r=-0.688,r=-0.566,p<0.01).LVex/in was positively correlated with RV and RV%/TLC(r=0.402,r=0.593,p<0.01).7.MLDex-MLDin was positively correlated with FVC,FEV1%and FEV1/FVC%(r=0.632,r=0.688,r=0.566,p<0.01).MLDex-MLDin was negatively correlated with RV and RV%/TLC(r=-0.506,r=-0.603,p<0.01).8.MLDex/in was negatively correlated with FVC,FEV1%and FEV1/FVC%(r=-0.611,r=-0.745,r=-0.659,p<0.01).MLDex/in was positively correlated with RV and RV%/TLC(r=0.517,r=0.599,p<0.01).3.summary1.CT lung function can accurately show the pathophysiological changes in COPD patients with the increase of GOLD level.2.Dual meteorological CT quantitative measurement of COPD patients are closely related of lung function in addition to LVin and FEV1%.In comparison with inspiratory phase,expiratory phase LVex,MLDex,EIex,Lvin-LVex,LVex/in,MLDex-MLDin and MLDex/in are more correlated with pulmonary function.It can be used as a reliable quantitative indicator of lung function.Dual meteorological CT quantitative measurement of COPD patients are closely related to RV and RV%/TLC of reflects the small airway lesions.CT quantitative indexes can reflect the small airway lesion.MLDex has the best correlation with RV and MLDex-MLDin has the best correlation with RV%/TLC.Therefore,the quantification index of expiratory CT are more valuable in predicting small airway disease in COPD patients.3.EI of Dual meteorological is significantly negatively correlated with FEV1%,FEV1/FVC%,DLCO,DLCO/VA,so EI not only evaluated the change of ventilatory function in COPD patients,but also evaluated the change of ventilatory function in COPD patients.EI of expiratory phase is more correlated with pulmonary function.Conclusions1.CT lung function can accurately quantify lung volume,mean lung density,emphysema index,etc and reflect the pathophysiology of the patient's lungs.It can be used as a substitute for lung function to diagnose patients.2.Biphasic CT quantitative measurements have significant correlation with clinical lung function.There were statistically significant differences in quantitative indices of biphasic CT between normal and COPD patients.The expiratory phase can not only be used as an inspiratory phase,but also the expiratory phase CT quantitative index is more relevant than the pulmonary function.It can be used as a reliable indicator of CT lung function tests.