The aims of this study are 1) to identify IVUS determinants of the CAMS-derived myocardial territories subtended to the diseased vessels, 2) to find IVUS determinant for the extent of CAMS-derived myocardial size, and 3) to develop the mathematical model that integrates the IVUS information about myocardial territory and stenosis severity and predicts the extent of CAMS-derived myocardial size.

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

patients who undergo coronary computed tomography angiography, invasive coronary angiography and IVUS assessment prior to intervention will be enrolled. The patients should have at least one coronary artery lesion (including non-left main and isolated left main disease) with visually estimated diameter stenosis >50%