The Correlation Between HRCT And Lung Function In Patients With Chronic Obstructive Pulmonary Disease

Objective: To evaluate airway lesions of COPD by HRCT, and analyzecorrelation of the lesions and PFT.Subjects and Methods：In48cases, there were20healthy controls,28patients with chronic obstructive pulmonary disease (COPD). All cases werestrictly selected except the diseases which impact the lung function, such asthoracic deformity, large pleural effusion, a large area of pulmonary infection,pulmonary mass of which the diameter is longer than4cm and so on. All caseswere completed HRCT and pulmonary function tests on the same day. The totallung was respectively scanned at full inspiration with MSCT. We use ThoracicVCAR software to directly measure airway wall relevant indicators: wallthickness (WT)、inner diameter（Din）、wall area（WA）and percentage of wallarea(WA%). We use SN65511-type pulmonary function tester to measure someindicators: forced expiratory volume at the first second%pre (FEV1%), ratio ofthe first second forced expiratory volume to forced vital capacity (FEV1/FVC),flow rate of50%of forced vital capacity exhaled%pre (FEF50%), flow rate of75%of forced vital capacity exhaled%pre (FEF75%), ratio of residual volumeto total lung capacity%pre (RV/TLC%), and diffusion capacity for carbonmonoxide of lung%pre (DLCO%). The repeatability was tested bySPSS19.0,and the CT indexes were analyzed the correlation with PFToutcomes.Results:1.Airway data: WT of the two groups is1.48±0.24mm and1.30±0.15mm, and has significant difference (F=9.574，P=0.003). Din of the two groups is2.67±0.40mm and3.36±0.20mm, and has significantdifference(F=6.273，P=0.000). WA of COPD group is20.63±3.49mm2,normal PFT is18.37±2.97mm2. There is statistical difference between thetwo groups (F=0.375，P=0.023). WA%of the two groups is73.43±5.48%and66.68±2.73%, and has significant difference (F=8.984，P=0.000).2.PFT data: FEV1/FVC of COPD group is55.39±10.34%, normal PET is88.73±6.60%. There is significant difference between the two groups(F=7.197，P=0.000). FVE1%of the two groups is42.01±16.81%and105.07±13.20%, and has significant difference(F=0.513，P=0.000). FEF50%of thetwo groups is29.06±9.61%and85.15±10.30%, and also has significantdifference(F=0.238，P=0.000). FEF75%of the two groups is45.68±14.29%and99.74±26.23%, and has significant difference(F=8.381,P=0.000).RV/TLC%of the two groups is142.66±22.11%and106.29±7.06%, and hassignificant difference(F=18.129，P=0.000). DLCO%of the two groups is43.76±17.98%and91.51±9.60%, and has significant difference(F=11.547，P=0.000).3.The correlation of HRCT and PFT data: Din is only negativelycorrelated with RV/TLC%(r=-0.385，P=0.048). WT is negatively correlatedwith FEV1%(r=-0.614，P=0.001). There is correlation between WA andFEV1%(r=-0.422， P=0.025), so is FEV1/FVC(r=-0.432， P=0.022),FEF50%(r=-0.406，P=0.029), and FEF75%(r=-0.393，P=0.042). WA%isnegatively correlated with FEV1%(r=-0.763，P=0.000), FEV1/FVC（r=-0.618，P=0.001）, FEF50%（r=-0.725， P=0.000）,and FEF75%（r=-0.604，P=0.001）.WA%is positively correlated with RV/TLC%(r=0.506，P=0.009). Conclusions:1.There were obvious differences between patients with COPD and thehealthy ones in airway lesions (WT、Din、WA、WA%) by HRCT.2.There is correlation between airway data (WT、WA、WA%) by HRCTand the functional data (FEV1/FVC、FEV1%p、FEF50%p、FEF75%p、RV/TLC%p),which WA%correlated best.3.The airway data (WT、WA、WA%) could forecast COPD usefully, betterto evaluate it.