Jang Yu Mi, Oh Yeon-Mok, Seo Joon Beom, Kim Namkug, Chae Eun Jin, Lee Young Kyung, Lee Sang Do
Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Invest Radiol. 2008 Jun;43(6):403-10. doi: 10.1097/RLI.0b013e31816901ab.
The purpose of this study is to evaluate the correlation of the perfusion parameters of 3-dimensional, contrast-enhanced magnetic resonance (MR) imaging (3D CEMRI) with pulmonary function test (PFT) and quantitative computed tomography (CT) parameters in patients with chronic obstructive pulmonary disease (COPD).
In 14 patients with COPD, 3D CEMRI was performed. From the signal intensity-time curves, pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time of each pixel was calculated. From the volumetric CT data, the quantitative parameters including the volume fraction of the lung below -950 Housefield Units (V(-950)) and mean lung density were assessed. The correlation between the MR perfusion parameters and the parameters from quantitative CT and PFT was assessed using Spearman correlation analysis. The correspondence of the regional impairment of perfusion on MR perfusion maps to the areas of emphysema on quantitative CT maps in each patient was assessed qualitatively using a 4-class visual scoring method by 2 readers.
All 3D CEMRI examinations were successfully completed and MR perfusion parameters were obtained in all patients. The Spearman correlation test showed that PBF positively correlated with forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) (R = 0.49, P = 0.044), PBV positively correlated with FEV(1)/FVC (R = 0.69, P = 0.006) and negatively correlated with V-950 (R = -0.61, P = 0.020), and mean transit time positively correlated with FEV(1) (R = 0.63, P = 0.017) and FEV(1)/FVC (R = 0.76, P = 0.002). The areas of perfusion impairment on PBF and PBV maps were relatively well correlated with the areas of emphysema on CT maps [very good or good: PBF 71.5% (reader 1) and 64.3% (reader 2) of the patients, kappa = 0.47 (P < 0.001); PBV 78.6% (reader 1) and 78.6% (reader 2) of the patients, kappa = 0.89 (P < 0.001)].
This study shows that the deterioration of perfusion parameters measured on MR in patients with COPD, correlates with worsening of airflow limitation on PFT and emphysema index on CT. Regional heterogeneity of emphysema on CT matches with the decreased perfusion on MR.
本研究旨在评估慢性阻塞性肺疾病（COPD）患者的三维对比增强磁共振成像（3D CEMRI）灌注参数与肺功能测试（PFT）及定量计算机断层扫描（CT）参数之间的相关性。
对14例COPD患者进行3D CEMRI检查。从信号强度-时间曲线计算每个像素的肺血流量（PBF）、肺血容量（PBV）和平均通过时间。从容积CT数据中评估包括低于-950 Hu的肺体积分数（V(-950)）和平均肺密度在内的定量参数。采用Spearman相关分析评估MR灌注参数与定量CT及PFT参数之间的相关性。由2名阅片者采用4级视觉评分法对每位患者MR灌注图上灌注损伤区域与定量CT图上肺气肿区域的对应关系进行定性评估。
所有3D CEMRI检查均成功完成，所有患者均获得MR灌注参数。Spearman相关检验显示，PBF与第1秒用力呼气容积（FEV(1)）/用力肺活量（FVC）呈正相关（R = 0.49，P = 0.044），PBV与FEV(1)/FVC呈正相关（R = 0.69，P = 0.006），与V-950呈负相关（R = -0.61，P = 0.020），平均通过时间与FEV(1)呈正相关（R = 0.63，P = 0.017），与FEV(1)/FVC呈正相关（R = 0.76，P = 0.002）。PBF和PBV图上的灌注损伤区域与CT图上的肺气肿区域相关性较好[非常好或好：PBF方面，71.5%（阅片者1）和64.3%（阅片者2）的患者，kappa = 0.47（P < 0.001）；PBV方面，78.6%（阅片者1）和78.6%（阅片者2）的患者，kappa = 0.89（P < 0.001）]。
本研究表明，COPD患者MR测量的灌注参数恶化与PFT气流受限恶化及CT肺气肿指数恶化相关。CT上肺气肿的区域异质性与MR上灌注降低相匹配。
