Clinical applications of cardiac magnetic resonance imaging.

As a direct result of the rapid technical progress which has been realized regarding hardware and software, cardiovascular magnetic resonance imaging (CMR) is increasingly established as an important method in the diagnosis of cardiovascular disease. Numerous clinical and experimental studies have demonstrated the equality or even superiority of CMR compared to other imaging modalities such as nuclear medicine or transthoracic echocardiography. Particular strengths of CMR are the ability to overcome anatomical limitations (such as poor acoustic window), a multimodality approach to comprehensively answer various aspects of cardiac disease, and the absence of ionizing radiation during the exam. Main clinical applications of CMR include assessment of ventricular function, myocardial viability, myocardial perfusion, valvular disease, differential diagnosis of inflammatory heart disease and cardiomyopathies, congenital heart disease and structural abnormalities. In the assessment of coronary artery disease (CAD) by CMR, analysis of global and regional myocardial function is enhanced by examination of myocardial viability and perfusion. This non-invasive diagnostic ''triad'' confers CMR a unique methodological strength for a comprehensive evaluation of CAD within one single exam session. In particular, late gadolinium enhancement scar imaging by CMR is currently the most accurate non-invasive method to examine myocardial viability. In several studies on the prognostic value of CMR in CAD assessment, normal adenosine-stress CMR was highly predictive for a good prognosis, thus able to identify patients in whom invasive coronary angiography can be deferred safely. Regarding myocarditis, CMR is evolving as the most accurate imaging technique. Challenges for future development of the role of CMR in clinical routine will most likely not only include technical improvement, but also a larger CMR scanner availability, optimized cost-efficiency, increased awareness and competence to be achieved by an extended education and training in CMR.