Objective: To investigate the application value of combination of 18F-FDG PET and ultrasound cardiogram in the assessment of patients with severe coronary heart diseases. Methods: A total of 38 patients with severe coronary heart diseases who were admitted to Beijing Anzhen Hospital from January 2015 to November 2015 were enrolled.There were 32 men and 6 women in this study, and the mean age was 33-73(59±10)years.All patients underwent coronary angiography, PET myocardial metabolic imaging, and echocardiography to evaluate the degree of myocardial ischemia, percentage of infarcted myocardium, left ventricular ejection fraction (LVEF), and left ventricular end-diastolic dimension (LVEDD). On the basis of the clinical experience of Beijing Anzhen Hospital, the study allocated these 38 patients to a CABG group (n=20), who underwent CABG, and a non-CABG group treated by medical therapy alone (n=18). Results: A significantly smaller amount of abnormal myocardium was seen in the CABG group (28.9%±6.3% vs 43.3%±4.5%; P<0.01). The percentage of infarcted myocardium was significantly smaller in the CABG group (13.0%±4.1% vs 24.2%±5.5%) (P<0.01). LVEF was significantly greater (45.3%±3.8% vs 36.1%±6.3%, P<0.01) and LVEDD significantly smaller (54.2 mm±7.1 mm vs 65.1 mm±5.8 mm) in the CABG group (P=0.003). Percentage of abnormal myocardium was moderately negatively correlated with LVEF (r=-0.603, P=0.006). Percentage of infarcted myocardium was mildly negatively correlated with LVEF (r=-0.477, P=0.039). CABG was performed without complications.The LVEF of A1 group before and after operation were 45.3%±3.8% vs 51.6%±9.3%(P=0.043). The cardiac function of the patients was improved obviously after operation.All patients were followed for 1-10 months after discharge.The cure rate was 100%. Conclusion: In patients with severe coronary heart diseases undergoing CABG, 18F-FDG PET myocardial metabolic imaging combined with echocardiography have great value, they can assist in preoperative evaluation.