COPD患者HRCT容积成像特点与肺功能的关系研究

Relationship between HRCT volume imaging characteristics and pulmonary function in patients with COPD

目的探讨慢性阻塞性肺疾病(COPD)患者高分辨CT(HRCT)容积成像特点与肺功能的关系。方法选取2011年3月至2015年2月十堰市郧阳区人民医院收治的62例COPD患者作为研究对象,所有患者均接受HRCT容积扫描及肺功能检查,图像传输至工作站,记录肺容积、肺密度各项参数,并按照COPD严重程度分组,分析HRCT参数与患者肺功能指标的相关性。结果随着COPD病情严重程度的上升,患者一秒用力呼气容积(FEV1)、用力肺活量(FVC)、一秒率(FEV1/FVC)、一秒用力呼吸容积占预计值比例(FEV1%)降低,残气量/肺总量(RV/TLC)上升;Ⅳ级COPD患者FEV1、FVC、FEV1/FVC、FEV1低于Ⅰ级者[(0.8±0.1)L、(2.2±0.3)L、(34.6±10.2)%、(56.3±3.6)%vs(2.3±0.3)L、(3.5±0.3)L、(81.6±8.3)%、(73.2±5.3)%],RV/TLC高于Ⅰ级者[(75.2±8.6)%vs(45.1±5.8)%],差异均有统计学意义(P<0.05);随着COPD病情严重程度的上升,患者深吸气、呼气末肺密度均上升;Ⅳ级COPD患者深吸气、呼吸末肺密度高于Ⅰ级者[(-956.8±22.4)HU、(-899.5±22.7)HU vs(-865.3±24.5)HU、-744.2±30.2)HU],差异均有统计学意义(P<0.05);其深吸气末容积(Vin)、深呼气末肺容积(Vex)上升,但差异均无统计学意义(P>0.05),仅Ⅱ级、Ⅲ级、Ⅳ级与Ⅰ级Vin对比,Ⅳ级与Ⅱ级Vin,Ⅲ级、Ⅳ级与Ⅰ级Vex对比差异有统计学意义(P<0.05);肺气肿体积(TEV)、肺气肿指数(EI)上升,Ⅳ级COPD患者TEV、EI高于Ⅰ级者[(1.1±0.2)L、(17.8±3.4)%vs(0.3±0.2)L、(6.1±4.2)%],差异均有统计学意义(P<0.05),但不同病情严重程度全肺体积(TLV)无明显变化(P>0.05);Vin与FVC、FEV1、FEV1/FVC相关,Vex、TEV、EI与所有肺功能指标均相关,深吸气肺密度、TLV与FEV1/FVC相关(P<0.05)。结论 HRCT容积成像可清晰显示COPD肺实质破坏,其定量参数与肺功能指标有较好的相关性,可用于评定COPD患者病情严重程度。

Objective To discuss the relationship between the high resolution CT（HRCT） volume imaging characteristics and pulmonary function in patients with chronic obstructive pulmonary disease（COPD）. Methods A total of sixty-two patients with COPD, who admitted to People＇s Hospital of Yuyang District of Shiyan City from March2011 to February 2015, were selected as the study subjects. All patients underwent HRCT volume scan and pulmonary function tests, and the images were transmitted to workstation. The parameters of lung volume and lung density were recorded and classified according to the severity of COPD. The correlations between HRCT parameters and pulmonary function were analyzed. Results With the increase of severity of COPD, the forced expiratory volume in one second（FEV1）, forced vital capacity（FVC）, second rate（FEV1/FVC） and percentage of forced expiratory volume in one second in expected value（FEV1%） decreased, while residual volume/total lung capacity（RV/TLC） increased. FEV1, FVC,FEV1/FVC and FEV1 of patients with grade Ⅳ COPD were（0.8±0.1） L,（2.2±0.3） L,（34.6±10.2）% and（56.3±3.6）%, respectively, which were significantly lower than（2.3 ± 0.3） L,（3.5 ± 0.3） L,（81.6 ± 8.3）%,（73.2 ± 5.3）% of patients with grade Ⅰ COPD（P0.05）, while RV/TLC was（75.2±8.6）%, which was significantly higher than（45.1±5.8）% of grade Ⅰ（P0.05）. The deep inspiration and lung density at the end of expiration of the patients increased with the aggravation of COPD（P0.05）; the deep inspiration and lung density at the end of expiration of patients with grade Ⅳ COPD were（-956.8±22.4） HU,（-899.5±22.7） HU, which were significantly higher than（-865.3±24.5） HU,（-744.2±30.20） HU of patients with grade Ⅰ（P0.05）. The volume at the end of deep inspiration（Vin） and expiratory volume at the end ofdeep expiration（Vex） increased in the two groups, but there were no significant differences between them（P0.05）.There were significant differences in Vin between grade Ⅱ, grade Ⅲ, grade Ⅳ and grade Ⅰ, in Vin between grade Ⅳand grade Ⅱ and in Vex between Ⅱ, grade Ⅲ, grade Ⅳ and grade Ⅰ（P0.05）. The emphysema volume（TEV） and emphysema index（EI） increased, TEV and EI of patients with grade Ⅳ COPD were（1.1±0.2） L and（17.8±3.4）%, respectively, which were higher tha（0.3±0.2） L,（6.1±4.2）% of patient with grade ⅠCOPD（P0.05）. There were no significant differences in total lung volume（TLV） between patients with different severity of disease（P0.05）; Vin was related to FVC, FEV1 and FEV1/FVC（P0.05）, while Vex, TEV and EI were related to all pulmonary function indexes（P0.05）.Deep inspiration lung density and TLV were related to FEV1/FVC（P0.05）. Conclusion HRCT volume imaging can clearly show COPD lung parenchyma destruction. Its quantitative parameters and pulmonary function indexes are well correlated, which can be used to determine the severity of COPD.