Cardiovascular magnetic resonance: Myocardial perfusion

There is growing evidence that the noninvasive assessment of myocardial per fusion with cardiovascular magnetic resonance is a valid and accurate tool for the assessment of ischemic heart disease and its introduction into rout ine clinical evaluation of patients is rapidly expected. Magnetic resonance measurements allow the evaluation of reversible and irre versible myocardial ischemia, the assessment of acute myocardial infarction , as well as the recognition and detection of viable myocardium. Magnetic r esonance perfusion measurements are mainly performed with TI-shortening con trast agents such as gadolinium-DTPA either by visual analysis or based on the analyses of signal intensity time curves. For the detection of myocardi al ischemia the first pass kinetics of a gadolinium-DTPA bolus and for the detection of myocardial necrosis and the definition of viable myocardium st eady state distribution kinetics are assessed. Quantitative analysis of myo cardial perfusion can be performed but requires complex modeling due to the characteristics of gadolinium-DTPA. Thus, semi-quantitative parameters are preferred. There is accumulating evidence in the literature that magnetic resonance imaging can be used for the detection of coronary artery stenosis with high diagnostic accuracy both with semi-quantitative or visual analys is. Myocardial infarction can be reliably detected and the infarcted area d etermined. Non-reperfused infarcted myocardium can be differentiated from r eperfused myocardium by different enhancement patterns that correlates with viability. Cardiac magnetic resonance is a promising technique that can combine differ ent functional studies during one examination, such as the assessment of wa ll motion and perfusion at rest and stress. With further improvements in an alysis software magnetic resonance perfusion measurement may rapidly become a routine tool for the assessment of patients with coronary artery disease .