The HRCT Findings Of Early Stage Small Airway Disease And The Correlation With Pulmonary Function Test

Objective： To detect imaging findings on end-inspiratory and end-expiratory HRCT in early stage small airway disease and analyz the correlation to the measures of pulmonary function tests(PFT).Methods：41small airway disease patients with cough，verified by pulmonary function tests，underwent end-inspiratory and end-expiratory HRCT scans.The41controls with cough and normal pulmonary function tests underwent the same scans.The correlation of findings of HRCT and the measures of PFT such as FEV1、FEF25%、FEF50%、 FEF75%、FEF25-75%were analysed.Results： The main HRCT findings of the patients group were Mosaic attenuation（60.98%）、air-trapping（56.10%）、bronchial wall thickening（29.27%）、tree-in-bud（9.76%）、 centrilobular nodule（7.32%）、bronchiolectasis（17.07%）、bronchiolar obstruction （14.63%）、ground-grass opacity（95.12%）. The main HRCT findings of the controls group were Mosaic attenuation（36.59%）、air-trapping（31.71%）、bronchial wall thickening（4.88%）、tree-in-bud（9.76%）、 centrilobular nodule（9.76%）、bronchiolectasis（9.76%）、bronchiolar obstruction （0）、ground-grass opacity（97.56%）.The incidence of Mosaic attenuation、air-trapping、bronchial wall thickening、bronchiolar obstruction in patients group was higher greatly than that in control group（P<0.05）. There were no significant differences between the patients group and the controls group in the incidences of others HRCT findings.Of all the HRCT findings，the incidence of Mosaic attenuation was correlated significantly with FEF75%、FEV1、FEF25-75%. The incidence of air-trapping was correlated significantly with FEF75%、FEV1and wasn’t correlated significantly with FEF25%、FEF50%、FEF25-75%. The incidence of bronchial wall thickening was correlated significantly with FEF75%、FEF50%、FEF25%、FEF25-75%、FFEV1，especially with FEF75%(r=-0.381，p<0.00). The incidence of bronchiolar obstruction was correlated significantly with FEF75%、FEF50%、FEF25-75%及FEV1(p<0.05).Conclusion： Mosaic attenuation、air-trapping、bronchial wall thickening、 bronchiolar obstruction were characteristic findings of small airway disease. The incidence of mosaic attenuation、air-trapping in expiration scan were more than that in inspiration scan. There were significant correlations of the incidence of the four above finding with FEF75%.The HRCT findings could reflect the function of small airway to some extent and were helpful to diagnose early stage small airway disease.