First Department of Internal Medicine, Shinshu University School of Medicine, Asahi, Matsumoto, Japan.
Respirology. 2010 Nov;15(8):1215-9. doi: 10.1111/j.1440-1843.2010.01853.x.
Lung uptake of iodine-123 metaiodobenzylguanidine (¹²³I-MIBG) is used as an indicator of pulmonary endothelial function. Decreased lung uptake of ¹²³I-MIBG has been demonstrated in patients with COPD as compared with normal subjects. The present study was performed to examine the relationship between lung uptake of ¹²³I-MIBG and pulmonary artery pressure (Ppa) at rest and during exercise, in patients with COPD.
¹²³I-MIBG scintigraphy was performed in 19 patients with COPD. Anterior planar images were acquired 15 min after the injection of ¹²³I-MIBG, and the total lung to upper mediastinum ratio (LMR) was calculated for both lungs. Right heart catheters were used to monitor Ppa continuously at rest and during exercise. Exercise was performed on an electrically braked bicycle ergometer at a constant workload of 25 W for 3 min.
In COPD patients the LMR were not correlated with the pulmonary function parameters measured before exercise, including FEV₁, PaO₂, DL(CO), or Ppa at rest. However, the percentage increase in Ppa during exercise was significantly correlated with LMR.
Evaluation of the kinetics of lung uptake of ¹²³I-MIBG may be a novel scintigraphic tool for the assessment of exercise-induced pulmonary hypertension in patients with COPD.
碘-123 间碘苄胍（¹²³I-MIBG）的肺摄取被用作肺内皮功能的指标。与正常受试者相比，COPD 患者¹²³I-MIBG 的肺摄取减少。本研究旨在检查 COPD 患者¹²³I-MIBG 的肺摄取与静息和运动时肺动脉压（Ppa）之间的关系。
对 19 例 COPD 患者进行¹²³I-MIBG 闪烁显像。¹²³I-MIBG 注射后 15 分钟采集前位平面图像，计算双肺的总肺/上纵隔比值（LMR）。使用右心导管连续监测静息和运动时的 Ppa。运动在电动制动自行车测功仪上以 25 W 的恒定工作负荷进行 3 分钟。
在 COPD 患者中，LMR 与运动前测量的肺功能参数（包括 FEV₁、PaO₂、DL(CO)或静息时的 Ppa）之间无相关性。然而，运动期间 Ppa 的百分比增加与 LMR 显著相关。
¹²³I-MIBG 肺摄取动力学的评估可能是评估 COPD 患者运动性肺动脉高压的一种新的闪烁显像工具。
