Prolonged lung retention of 123I-IMP in pulmonary disease.

The accumulation of venously injected 123I-IMP in the lung was studied. Between 30 and 50 min after the injection of the 1.5 mCi 123I-IMP, the concentration of 123I-IMP in the broncho-alveolar lavage fluid were much higher than in the blood. It was considered that 123I-IMP was transported into the alveolar spaces and was absorbed by the alveolar cells. The half time (T1/2) of the 123I-IMP release from the lung between 10 and 25 min immediately after the injection was calculated. In normal subjects the T1/2 ranged between 25 and 44 min and was prolonged in subjects with pulmonary fibrosis, sarcoidosis, and allergic alveolitis. It was considered that the retention of 123I-IMP was related not only to the endothelial cells, but also to the alveolar cells. It was considered that the analysis of the lung release of 123I-IMP forms a new lung dysfunction index.