A trial of pulmonary scintigraphy using I-123 IMP with a property of high lung uptake

We performed pulmonary scintigraphy using N-isopropyl-p-[123I]iodoamphetamine (I-123 IMP) with a property of high lung uptake. For 20 min after intravenous bolus injection of I-123 IMP 3 mCi, data were recorded with a large-field γ camera and digital computer. Then both planar and single photon emission CT (SPECT) images were acquired. The results were as follows: 1. In normal cases, I-123 IMP showed a high lung uptake in the first pass and subsequent slow clearance. 2. In normal cases, both planar and SPECT images of lung with I-123 IMP were similar to those of Tc-99m MAA perfusion scintigraphy. 3. In two cases with lung cancer who received radiotherapy, there was a discrepancy in the image between I-123 IMP and Tc-99m MAA, probably because of very slow clearance of I-123 IMP from the irradiated area. 4. Pulmonary scintigraphy using I-123 IMP has a possibility that reflects the non-respiratory lung function, so we expect this method will become a new approach for the evaluation of pulmonary diseases. (author)