Diagnostic value of perfusion cardiovascular magnetic resonance in patients with angina pectoris but normal coronary angiograms assessed by intracoronary acetylcholine testing.

Background: Perfusion cardiovascular magnetic resonance (CMR) has a high sensitivity for the detection of significant coronary artery disease (CAD). However, the specificity of this method is lower than its sensitivity. The reason for this observation is hitherto unclear and has been either explained by 'false-positive' results or by microvascular dysfunction in patients without CAD.