Flow and motion: implications on cardiac MR

The field of cardiac MR is becoming an increasingly important area of research and development. Recent improvements in system hardware are in part driven by and in part driving the very rapid progress that is being made in the area. The relatively slow initial development has been a result of the very complex and to a large extent unpredictable nature of the motion of the heart itself and blood flow within it. An understanding of these issues has been important for two reasons. Firstly, to develop methods of improving image quality in the presence of such flows and motions and secondly to measure these physiological parameters, that may have important implications to the status of the cardiovascular system, for guidance and monitoring of clinical intervention. This paper overviews the issues and problems of flow and motion on MR. It then discusses the methods that have been developed to address and reduce the impact of these and also describes some of the approaches to measuring these parameters.