Characteristics Of COPD Phenotypes Classified According To The HRCT And Quantitative CT Research

Objective To classify the high-resolution CT(HRCT) phenotypes of COPD, and toinvestigate the clinical characteristics of various phenotypes and the relationship withpulmonary function tests and clinical features。Materials and methods collections of108COPD patients admitted to the FirstAffiliated Hospital of Guangzhou Medicial College, Guangzhou Institute of RespiratoryDiseases in February2009to Februaary2011.73cases were male,and35were female,aged46-78years, the average age was (66±7) years.With COPD were studied,thepatients were classified into four levels by GOLD,31cases belonged to level1,39cases belonged to level2,26cases belonged to level3,12cases belonged level4. At theend of maximum inspiratory and maximum end-expiratory breath-hold scan, wereclassified according to the degree of bronchial wall thicking in HRCT images and CTpulmonary function tests in emphyseme.Results According to the degree of bronchial wall thickening and emphysema exent,COPD patients were classified into5phenototypes:(1) Phenotype A,28cases, no ormild emphysema, with or without bronchial wall thickening;(2) Phenotype M1,19cases, moderate emphysema with bronchial wall thickening;(3) Phenotype M2t,12cases, there are severe or extremely severe emphysema and bronchial wall thickening;(4) Phenotype E1,35patients, moderate emphysema, without bronchial wall thickening;(5)Phenotype E2,14cases, with heavy or extremely severe emphysema, no bronchialwall thickening. The5phenotypes of COPD showed different characteristics in several aspects. Patients with phenotype A and E1showed a higher body mass index（23.0±1.9，23.4±3.3）kg/m2vs phenotype E2（19.3±3.6）kg/m2and phenotype M1（22.6±3.0）kg/m2and phenotype M2（20.0±2.4）kg/m2，F=7.679，P＜0.01. TheFEV1%and FEV1/FVC in phenotype A [（75.6±15.8）%and (62.8±8.0)] were betterthan other each model, the difference was statistically significant, F=7.076and15.111，P＜0.01.The RV in phenotype M2was the largest, for the average （184.8±52.1）, thedifference was statistically significant,(F=5.077, P <0.05). The RV/TLC inphenotype M2was higher than other each model, the difference was statisticallysignificant,(F=6.974, P <0.01). No significant difference between the group ofpatients with TLC. Inhale and exhale in phase CT lung function in the check index:phenotype A patient lung CT, respectively, in an average （-877.2±28.5，-761.7±25.3）HU, higher than other each model, the difference was statistically significant,(F=20.131and90.595, P <0.01); E2phenotype gas in the lungs total volume, respectively（5618.1±961.9,4131.4±1143.6）cm3, more than any other each model, the differencewas statistically significant,(F=5.933and28.691, P <0.01); Patients with phenotype Aunit volume density maximum, respectively （0.1201±0.0217,0.2338±0.0302)g/cm3,each are statistically significant differences between the,(F=18.931and66.108, P <0.01); E2phenotype patients respectively emphysema volume （4219.4±898.1，2470.3±1191.9）, higher than other each model, the difference was statisticallysignificant,(F=20.120and71.347, P <0.01).Conclusion Various morphological phenotypes of COPD based on HRCT showeddifferent clinical characteristics、Conventional lung function, CT lung function.