基于分形学理论评价低氧性肺血管重塑

目的 应用分析维数方法评价慢性阻塞性肺疾病(COPD)患者肺血管树空间结构重塑随氧分压的变化规律.方法 分别对106例COPD患者及100例非COPD健康对照者进行CT扫描并进行血气分析.应用后处理软件形成肺血管树,以ImageJ软件计算外周肺血管树分形维数(FD);比较对照组与COPD组FD值;分析COPD患者FD改变与动脉血氧分压的相关性.结果 COPD组外周肺血管树FD显著低于对照组(t=5.21,P＜0.01).COPD患者FD与动脉血氧分压存在显著正相关性(r=0.692,P＜0.01).结论 FD分析能够有效评估COPD患者病程中肺小血管(动脉及静脉)重塑,COPD患者肺血管树FD值与氧分压显著相关,一定程度验证了低氧在肺血管重塑过程中的作用.

Evaluation of hypoxic pulmonary vascular remodeling based on fractal theory

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.