MR perfusion in the detection of myocardial ischemia

Chest pain accounts for a large number of patients seeking care from a physician. The differential diagnosis, however, can be broad. The need to diagnose or exclude ischemic heart disease is important in this respect. Severity and extent of myocardial ischemia are for instance directly related to prognosis. Besides, coronary revascularization is guided not only by coronary stenosis morphology but also by its hemodynamic consequences. Of course in a large number of cases myocardial ischemia can be made improbable by means of history, physical examination and resting ECG. This still leaves a large number of patients with stable chest pain for whom the existence of significant coronary artery disease (CAD) or the severity and extent of myocardial ischemia is unclear. Non-invasive methods deter¬mine the need for invasive coronary angiography (CAG) combined with revascularization, thereby reducing the pure number of diagnostic CAG's. In this respect, the assessment of function has incremental value over morphology alone. Methods resembling physical exercise or inducing a stress response (by means of a pharmacological stressor) are widely used for this indication. Wellknown "stress" -tests for the detection of myocardial ischemia, such as for instance bicycle exercise testing or SPECT-imaging are limited in their diagnostic accuracy, radiation burden and/ or spatial resolution. The current status of MRI enables us to overcome these problems.