MRI at 7.0 Tesla is the new frontier to be explored in human research. However, no 7.0T human scanner is presently available for extramural research in the state of Maryland. We propose to acquire a 7.0 Tesla wide-bore MRI instrument to upgrade the F.M. Kirby Research Center for Functional Brain Imaging at the Kennedy Krieger Institute to a state of the art very-high field MRI facility. Investigators at the Kennedy Krieger Institute, Johns Hopkins University, and the University of Maryland presently have 28 NIH-funded grants (see Tables 1, 2) with several aims that can strongly benefit from the improved technical capabilities at the high field strength of 7.0T compared to the presently available equipment. These investigators presently use the 1.5T and 3.0T systems in the F.M. Kirby Research Center for brain and cardiac studies related to functional MRI, quantitative physiological MRI (e.g. absolute blood flow experiments), magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI), and diffusion tensor imaging (DTI). This proposed 7 Tesla instrument will provide the following benefits for the users: 1) All studies will benefit from the increased signal-to-noise ratio (SNR) proportional to the field. Such an increase in SNR would allow either a reduction in scan time with the square of the field or an increase in spatial resolution (voxel size) linear with the field. This is important for all studies listed in this application. 2) Several of the projects study functional MRI using the BOLD effect, which increases at least linearly with the magnetic field. It has also been shown that BOLD data at high field reflect more of the microvasculature instead of large vessels. In addition, spin-echo BOLD effect may become better measurable, allowing their use for the study of frontal lobe and in the quantification of physiological parameters. 3) The prolonged T1 at high field should allow improved sensitivity for arterial spin-labeling studies of absolute cerebral blood flow. 4) Spectroscopy studies should benefit from the increased chemical shift separation. Furthermore, coupled spins, such as those in glutamate, glutamine, and myoinositol, should become better distinguishable as they approach the weak-coupling limit. Heteronuclear spins and water-exchangeable protons will be more easily measurable at high fields, the latter leading to completely new imaging possibilities. This 7T whole-body upgrade is essential for continued high-quality state-of-the-art research at our institutions and for the national facilities provided by our Research Resource.
