Iodine-123-HIPDM lung imaging in pulmonary vein-banded pulmonary hypertension.

To evaluate the use of N,N,N'-trimethyl-N,-[2-hydroxy-3-methyl-5 iodobenzyl-1, 3 propanediamine iodine-123 (HIPDM) in lung imagings for the diagnosis of individual pulmonary vein stenosis, 14 single-pulmonary vein-banded rats underwent lung imaging. After i.v. injection of 250-300 microCi [123I]HIPDM lung images were recorded at 2 min by a gamma camera interfaced with a PDP computer. Banded lung demonstrated higher [123I]HIPDM radioactivity than that of nonbanded lungs. The activity ratio of banded-to-nonbanded lungs ranged from 4.0 to 1.22 (average 1.62). Technetium-99m-macroaggregated albumin (MAA) lung images showed decreased perfusion in banded lung, and normal perfusion in the nonbanded lung. Postmortem microscopic changes in pulmonary arteries and veins were compatible with the elevated pulmonary artery and venous pressure in vein-banded lung. Whether the high uptake of [123I]HIPDM in banded lungs relates to endothelial receptors for HIPDM is unknown. Nevertheless, the finding of high lung uptake in banded lung in [123I]HIPDM lung imaging may be potentially used to diagnose individual pulmonary vein stenosis.