Objective To evaluate the feasibility and diagnostic accuracy of firstpass and delayed enhancement of dual-energy computed tomography(DECT) in myocardial perfusion imaging for detecting myocardial viability compared with 99mTcMIBI myocardial perfusion imaging. Methods Twenty-eight patients with coronary artery disease were detected by first-pass and delayed enhancement (5min) DECT and 99mTc-MIBI PET respectively. A color-coded iodine map was used to evaluate the myocardial perfusion defects. Myocardial perfusion defects according to the firstpass and delayed enhancement were compared with 99mTc-MIBI myocardial perfusion imaging on a segmental basis. Results A total of 476 myocardial segments of 28 patients were analyzed. 371 segments showed perfusion decrease or defects on first-pass DECT, while 156 segments low perfusion and 215 segments relatively high perfusion on delayed enhancement DECT. 237 segments perfusion decrease or defects showed on 99mTc-MIBI myocardial perfusion imaging. Analysis is the assessment of myocardial viability revealed better agreement among 13 myocardial segments(kappa=1), good agreement among the left 4(2/3/8/9) myocardial segments(0.40 ＜kappa＜0.75).The 8th segments had the highest sensitivity(100%), the 12th segments had the highest specificity(100%), and the 12th segments had the highest accuracy(92.85%). Conclusion There is high agreement between first-pass and delayed enhancement of dual-energy computed tomography(DECT) and 99mTc-MIBI myocardial perfusion imaging for detecting myocardial viability, which is a promising method to location Myocardial infarction, and evaluate myocardial viability.