Myocardial perfusion single photon emission computerized tomography (SPECT) is known as a gold standard method in detecting silent myocardial ischemia in asymptomatic patients with diabetes. Despite of the power of detecting myocardial ischemia functionally, there are limitations of SPECT in diagnosing subclinical coronary atherosclerosis anatomically. In recent advance in technology, coronary CT angiography (CTA) could detect subclinical coronary atherosclerosis. However, there is a paucity of information comparing the diagnostic power between SPECT and CTA.