[Estimation of 123I-metaiodobenzylguanidine lung uptake in heart and lung diseases--with reference to lung uptake ratio and decrease of lung uptake].

123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was performed in 64 patients with heart and lung diseases. Distribution of MIBG in the chest was evaluated by planar images, using counts ratios of the heart to the mediastinum (H/M) and the unilateral lung to the mediastinum (Lu/M). Most of patients with heart diseases showed obvious lung uptake of MIBG. The ratios of H/M were 1.75 +/- 0.20 in the group without heart failure and 1.55 +/- 0.19 in the group with heart failure. The ratios of Lu/M in the right and left lung were 1.56 +/- 0.16 and 1.28 +/- 0.16 in the group without heart failure. And those were 1.45 +/- 0.16 and 1.19 +/- 0.15 in the group with heart failure. But 3 patients complicated with chronic pulmonary emphysema and one patient with interstitial pneumonia due to dermatomyositis showed markedly decreased lung uptake. The ratios of Lu/M in the right and left lung of these patients were 1.20, 1.17; 1.17, 1.13; 1.01, 0.97 and 1.27, 0.94, respectively. These results suggest that the lung uptake of MIBG may reflect the state of pulmonary endothelial cell function in clinical situations, considering that it has been demonstrated that MIBG may be useful as a marker of pulmonary endothelial cell function in the isolated rat lung.