The Clinical Application Value Of Quantitative HRCT Measurement Of Pulmonary Small Blood Vessels Area In Chronic Obstructive Pulmonary Disease

Objective:In addition to small airway remodeling and emphysema,which are the cardinal features of COPD,vascular remodeling and arteriosclerosis caused by the systemic inflammation are also involved in the pathogenesis of COPD,The aim of this study was to assess and analyze the quantitative measurement of CSA of subsegmental and sub-subsegmental pulmonary small vessels from HRCT axial images between the patients in COPD and normal control group,and evaluated the pulmonary vascular alteration of total CSA with correlation of the extent of emphysema as well as clinical pulmonary function test indexes.To investigate the role of the percentage of the total cross-sectional area of small pulmonary vessels in the lung axial area(%CSA)from high resolution computed tomography(HRCT)in evaluating the severity of chronic obstructive pulmonary disease(COPD).Materials and Methods:One hundred COPD patients and 100 normal subjects underwent chest HRCT scans and all data were analyzed,retrospectively.All COPD patients underwent pulmonary function tests(PFT)after CT scans within two weeks,the test indexes including the ratio of forced expiratory volume in one second and forced vital capacity(FEV1/FVC)?the percentage of forced expiratory volume in one second predicted(FEV1pred%),and the percentage of diffusing capacity of the lung for carbon monoxid(DLCOpred%).The%CSA less than 5mm~2 and 5-10 mm~2 for the pulmonary(%CSA<5 and%CSA 5-10)of small vessels area were measured with Image J image-processing program.Comparison of%CSA<5 and%CSA 5-10between the COPD and control groups was performed using t test,and t The correlation between%CSA and PFT was evaluated by the Spearman and Pearson rank correlation test.The sensitivity and specificity of%CSA to diagnose COPD and the best cutoff were calculated from areas under the ROC curves.Results:%CSA<5 of COPD patients and control group were(0.44±0.20)%and(0.74±0.24)%(t=t=-5.52,P<0.01),respectively.%CSA 5-10 of the two groups were(0.20±0.08)%and(0.41±0.21)%(t=-4.07,P<0.01),respectively.The AUC values of%CSA<5 and%CSA 5-10 were0.895 and 0.724,respectively.When the best cut-off values of%CSA<5 and%CSA 5-10 were51.4%and 23.8%,the sensitivities and specificities were 89.5%and 72.4%,84.2%and 81%,respectively.%CSA<5 in COPD patients correlated positively with both FEV1%?FEV1/FVC and DLCOpred%(r=0.259?0.285 and 0.407,P<0.01,respectively).Both%%CSA<5 and CSA 5-10 in COPD patients correlated significant negatively with age and LAV%.Conclusion:The measurement and analysis of pulmonary Small vessels as%CSA<5and%CSA 5-10 in HRCT images correlated with PFTs in clinical and the severity degree of emphysema that presented as LAV%.which also played an important role in evaluating the severity of COPD.