Combined study using I-123 fatty acid and thallium-201 to identify ischemic myocardium

Ten patients with a history of myocardial infarction were examined by Tl/BMIPP imaging, i.e., the combination of resting perfusion imaging with Tl-201 and fatty acid metabolic imaging with I-123 β-methyl iodophenyl pentadecanoic acid (BMIPP). They also underwent positron emission computed tomography (PET) with F-18 fluorodeoxyglucose (FDG) in fasting. The left ventricular myocardium was divided into 7 segments to examine the relationship between the presence or absence of mismatch pattern on Tl/BMIPP images and the uptake of FDG. Of a total of 33 ischemic zones on Tl images, 8 had a more decreased Tl uptake than BMIPP uptake. Seven of the 8 (88%) had the uptake of FDG on PET images. On the other hand, of 25 zones with no evidence of mismatch pattern on Tl/BMIPP images, only 5 (20%) had the uptake of FDG. Myocardial zones with a great mismatch pattern on Tl/BMIPP images corresponded well to those showing the uptake of FDG, suggesting the likelihood of viability in ischemic myocardium. In addition, a decreased uptake of BMIPP in such myocardial zones was supposed to reflect the transition from metabolic fatty acid to glucose in ischemic myocardium. (N.K.)