Systemic and regional myocardial distribution of 123I-BMIPP in normal subjects

We estimated the systemic and left ventricular (LV) regional myocardial distribution of 123I-BMIPP (β-methyl-p-iodophenyl-pentadecanoic-acid) in normal subjects (n=13, mean age 43.9). In planar studies, the count ratios of heart, lung and liver to mediastinum were 2.63, 1.28 and 3.80 in the early images, and 2.23, 1.20 and 2.26 in the delayed images, respectively. The uptake in liver was almost identical with that in heart in the delayed images. In SPECT studies, the regional relative counts in anterior, septal, posterior and lateral LV walls were 100, 98, 96 and 108 (%) in the initial images, and 100, 98, 99 and 107 (%) in the delayed images, respectively. The regional relative uptake was sigrificantly higher in the lateral wall than those in the other parts of LV walls in both images. The relative counts in the basal, mid- and apical portions were 100, 111 and 87 (%) in the initial images, and 100, 113, 92 (%) in the delayed images, respectively. These results suggest that the myocardial regional distribution of BMIPP is not always uniform even in normal subjects. Thus, it is necessary to interpret with caution in the light of these findings, especially for detect in a myocardial lesion in an early phase of cardiomyopathy or a mild myocardial ischemia. (author)