Magnetic resonance imaging in the detection of myocardial viability: the role of delayed contrast hyperenhancement.

has emerged as a new noninvasive modality in the investigation of cardiovascular disease during the last decade. Cardiovascular magnetic resonance (CMR) has well-established imaging capabilities for the assessment of global and regional left ventricular (LV) function and mass. Its potential for the assessment of ischaemic heart disease is currently being explored in many centres. The main focus is currently myocardial tissue characterisation, aiming to detect the ischaemic myocardium and myocardial scar. Capabilities for myocardial characterisation have been greatly improved with the introduction of the delayed-enhancement technique, following injection of gadolinium-based contrast agents. CMR versatility also includes coronary magnetic resonance angiography, plaque imaging and blood flow measurements. In this article, we will review the rapidly expanding role of delayed contrastenhanced CMR in myocardial scar imaging and in guiding management of ischaemic cardiomyopathy. Absolute contraindications to CMR at present include permanent pacemakers, defibrillators, and cerebral aneurysm clips, although recent studies suggest that newer devices may be safe. Prosthetic heart valves and coronary artery stents are safe, although