Myocardial SPECT Imaging Using ¹²³I-m-lodobenzylguanidine

—A Comparative Study with ²⁰¹Tl—

Abstract

Myocardial SPECT imaging using ¹²³I-MIBG was performed in 29 patients with cardiac disorders and compared with the results of ²⁰¹Tl SPECT imaging. The areas with decreased uptake of ¹²³I-MIBG was usually more extended than those observed with ²⁰¹Tl SPECT, which was more prominent in the delayed scan than in the early scan. In the 2 patients out of 4 with hypertrophic cardiomyopathy, the distribution of ¹²³I-MIBG and ²⁰¹Tl was not matched. Namely, high uptake of ¹²³I-MIBG was observed in the regions with low ²⁰¹Tl uptake. The washout rate for ¹²³I-MIBG was higher in the region with decreased myocardial wall motion than those with preserved wall motion.