This study aims to evaluate whether quantitative analysis of coronary MR angiogram would improve the detection of functionally-significant coronary artery stenosis.

Coronary MR angiography is performed with a 3.0-T imager with 32-channel coils. Qunatitative analysis of coronary MR angiogram is evaluated on the basis of the signal intensity (SI) profile along the vessel. Quantitative analysis of coronary MR angiogram (QCMRA) is calculated as [1 - (SImin/SIref)] x 100, where SImin is minimal SI and SIref is corresponding reference SI. Diagnostic performance of quantitative analysis of coronary MR angiogram for predicting functional significant coronary stenosis was evaluated by using fractional flow reserve (FFR) as the reference standard.

Inclusion Criteria:

• Age ≥ 18 years
• 1 or more coronary stenoses in the major coronary artery with a vessel diameter ≥ 2mm on coronary MR angiogram
• Patient who were planned to undergo invasive coronary angiography and fractional flow reserve

Exclusion Criteria:

• clinically unstable patient
• a history of coronary revascularization
• infiltrative cardiomyopathy, hypertropic cardiomyopathy, myocarditis
• contraindication to use of adenosine
• complete occlusion of target lesion

Patients with coronary stenosis on coronary MR angiograms who were planned to undergo invasive coronary angiography.