RESUMO
Objective To evaluate the relationship between the spatial structure of pulmonary vascular tree and oxygen partial pressure in patients with chronic obstructive pulmonary disease(COPD) by the fractal dimension method.Methods 106 patients with COPD and 100 healthy people without COPD as controls were included in this study.All of the patients underwent multidetector CT scan and blood gas analysis.The pulmonary vascular trees were generated using post-processing software,and the FD of the pulmonary vascular trees were determined with ImageJ software in a personal computer.The fractal dimension were evaluated in the two groups.The relationship between FD and oxygen partial pressure in patients with COPD was analyzed.Results The FD value of the patients with COPD was lower than that of the patients without COPD (t =5.21,P＜ 0.01).There was a significant correlation between FD and the PaO2 in patients with COPD (r=0.692,P＜ 0.01).Conclusion FD analysis can effectively evaluate the process of pulmonary vascular remodeling induced by hypoxia in patients with COPD,which may be used as an important index for quantitative evaluation of pulmonary vascular remodeling in the course of COPD.