[Assessment of regional myocardial blood flow and energy metabolism]

Regional myocardial perfusion and metabolism were evaluated in coronary artery disease with positron emission computed tomography (PET). Regional myocardial perfusion was assessed after the intravenous administration of 13N-ammonia at rest and during exercise loading, using a supine ergometer. In some cases, 18F-FDG was administered at rest, and compared with 13N-ammonia. 13N-ammonia revealed hypoperfusion in coronary artery disease, in 73% of cases at rest and in 97%, during exercise study. Increased accumulations of 18F-FDG were observed in the peri-infarcted areas with decreased perfusions, and in the regions with normal perfusions at rest, where the exercise study showed transient ischemia. These results indicate that PET can detect regional myocardial ischemia with superior sensitivity, and that it provides a means of evaluating myocardial metabolism in vivo.