MOTION OPPONENCY IN HUMAN VISUAL CORTEX

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Work has focused during the past year on a number of fast imaging applications for body imaging. There has been a strong emphasis on the improvement of the so-called comprehensive cardiac exam. Magnetic resonance imaging has the potential of providing information about the heart unparalleled by any other exam. Current workups for cardiac disease usually require multiple tests, some of which are invasive. These tests include echocardiography, coronary angiography and radionuclide imaging, with and without stress. In order for MRI to provide the comprehensive cardiac exam, it must be able to characterize myocardial function and myocardial perfusion and identify coronary artery diseases. In the past, MR techniques were available for each of these tasks, but usually not in a fashion that they could all be performed in sequence at one sitting. Recent advances in fast imaging and the coupling of these capabilities with new novel intravascular contrast agents has allowed all of the elements for the comprehensive cardiac exam to meet this requirement. Myocardial perfusion is obtained in a first pass multi-slice study where transit of contrast through the myocardium can visualize areas of decreased myocardial perfusion. At equilibrium, these intravascular contrast agents allow fast 3D cine images to evaluate the entire heart with attention to myocardial function and motion to be evaluated in approximately 3-5 min. Because of the intravascular nature of this contrast agent, the relative contrast remains constant over a reasonable period of time allowing coronary artery imaging to be performed with high contrast. Our work will continue to take advantage of the improvements in scanner performance coupled with contrast agents to provide unique non-invasive data about the cardiovascular system.