[The relationship between N-isopropyl-p-[123I]iodoamphetamine accumulation in the brain and its dynamics in other...

Single photon emission computed tomography of the brain and dynamic scintigraphy of the lung and liver with N-isopropyl-p-[123I]iodoamphetamine (IMP) were performed in 21 patients with and without cerebrovascular diseases to determine the relationship between IMP accumulation in the brain and its dynamics in other organs. The D/E ratios of the lung, liver and brain were calculated dividing the counts of the delayed image by that of the early image. The brain D/E ratio in the normal hemisphere was well correlated with the lung D/E ratio. So cases which showed more rapid lung washout tended to washout faster from the brain. We thought that this fact was affected by the systemic circulation. And the values of the brain D/E ratio of the cerebrovascular disease group were larger than that of the non-cerebrovascular disease group. This suggest the frequent existence of arteriosclerotic changes in patients of the cerebrovascular disease. Because the local brain washout was depended on the amount of the cerebral blood flow there. On the other hand, the lung D/E ratio was inversely correlated with the liver D/E ratio. In other words, more washout from the lung caused more accumulation of IMP in the liver. Also the brain D/E ratio was inversely correlated with the liver D/E ratio. In conclusion, there was a close relationship between IMP dynamics in the brain and that in other organs.