RESUMO
Magnetic resonance imaging (MRI) is a diagnostic technique used clinically in cardiology over the last ten years. It offers great advantages over other methods as it is noninvasive, does not use radiation, is tomographic and multiplanar. MRI is a very flexible technique based on the interaction between atomic nuclei, usually hydrogen, and external magnetic fields. This leads to image formation and to other important functional diagnostic information. MRI has undergone great technical developments and has proven to be most useful in several areas: cardiovascular structure; global and regional cardiac function; cardiovascular flow; coronary anatomy; myocardial perfusion and metabolism. The initial clinical diagnostic goals of MRI were mainly the anatomic characterization of aortic pathology, congenital heart disease, pericardium diseases and cardiac masses. With the development of cine MRI and, more recently, with rapid imaging and flow evaluation techniques, it has been increasingly used in the functional assessment of cardiovascular diseases. The functional study of the above mentioned clinical pathologies is now possible and information can also be obtained in other important areas; cardiac volumes and function; cardiovascular shunts, valvular heart disease; ischemic heart disease (ischemia detection, infarction quantification, coronary anatomy and flow). It also has an important role in myocardial characterization and is promising for myocardial metabolism, evaluated by spectroscopy. The goal of this review is the presentation of the main MRI techniques and the present clinical applications of this imaging method in cardiovascular diagnosis.
