Regional myocardial perfusion and glucose metabolism were evaluated by positron emission tomography (PET) in children with coronary artery disease. Also, PET findings were compared with those of thallium-201 myocardial single photon computed tomography (SPECT). The study patients consisted of 11 children ranging in age from 3 to 14 years. Ten patients had significantly stenotic coronary arterial lesions due to Kawasaki disease, and one patient had a left coronary artery with an anomalous origin from the pulmonary artery. Evaluation was made before and after surgical revascularization in 3 patients. Regional myocardial perfusion was assessed at rest using 13N-ammonia, and regional myocardial glucose metabolism was assessed at rest under fasting conditions using 18F-fluorodeoxyglucose (18FDG). SPECT was performed after dipyridamole infusion. Initial and delayed images were obtained 7 min and 3 hrs after dipyridamole infusion, respectively. Left ventricular myocardial images were categorized as the septal, anterior, lateral, apical, and inferior segments, and evaluation was made for each segment. A total of 70 myocardial segments in 11 patients were classified into 4 groups according to the PET findings: 1) segments with normal perfusion and without enhanced 18FDG uptake (normal segments; n = 55), 2) normal perfusion with enhanced 18FDG uptake (metabolically abnormal segments; n = 3), 3) hypoperfusion with enhanced 18FDG uptake (ischemic but viable segments; n = 9), and 4) hypoperfusion without enhanced 18FDG uptake (non-viable segments; n = 3). On SPECT, the numbers of myocardial segments showing no perfusion defects, complete redistribution, incomplete redistribution, and persistent perfusion defects were 38, 12, 14, and 6, respectively. Comparisons were made between PET findings and SPECT findings.(ABSTRACT TRUNCATED AT 250 WORDS)