Intravascular Ultrasound Prediction of Myocardial Size and Coronary Computed Tomography-Derived Ischemic Burden for Coronary Lesion

Inclusion Criteria: * Age 20years or older * Patients who have at least one epicardial coronary artery lesion (including isolated left main disease or side branch) with visually estimated diameter stenosis \>50% and take coronary angiography, CT angiography and IVUS * Willing and able to provide informed written consent Exclusion Criteria: * In-stent restenosis * Bypass graft * Suspected coronary spasm even after sufficient nitrate injected * Cases in which the IVUS imaging catheter failed to cross the lesion * Poor quality IVUS or CT images * Visible collateral flow on angiography