Partial funding is requested for a 15 Tesla 110 mm inside diameter horizontal bore magnet system to be the central component in a unique state-of-the-art MR scanner facility that will serve a large NIH-funded geographically diverse user community encompassing a wide variety of biomedical disciplines. We currently serve users (our own investigators, collaborators and outside researchers) both within the MGH/Harvard/MIT system as well as from around the greater Boston/Cambridge region. However, current users do not get sufficient magnet access, and many others would like to take similar advantage of our facilities, but cannot readily do so: our current small-bore (nonclinical) MR instruments are overscheduled, in many cases operating on a 24x7 basis. The requested equipment would greatly expand our capacity to serve the local NIH-funded user community, as well as offer important new features to the user base. In particular, the proposed high field horizontal magnet would eliminate the serious limitations associated with keeping animals (especially those with compromised physiology) alive and well in the vertical position in conventional vertical very high field magnets; provide fast and powerful gradients (-600 mT/m, -100 us risetime, unavailable on any of our horizontal systems) for EPI, diffusion and high spatial resolution studies; the robustness, reliability, convenience and high throughput of a clinical console, and extraordinarily high magnetic field strength for outstanding signal-to-noise ratio, chemical shift dispersion and susceptibility- based contrast. The institutions to be served include MGH (radiology, cardiology, anesthesia and medicine), Children's Hospital (orthopedic surgery), Boston University School of Medicine (medicine), Tufts University (biomedical engineering), and Beth Israel Deaconess Medical Center (orthopedic surgery and oncology). Projects include studies of cardiac hypertrophy and failure, tracking of cardiac stem cells, NO synthase and ventricular remodeling, NO synthase and atherosclerosis, inhaled NO and anesthesia, neural mechanisms of acupuncture, dopamine mediated neurovascular coupling, ferrite nanoparticle-based contrast in fMRI, perfusion imaging, MR measurement of bone mineralization, diabetes and T-lymphocytes, tissue engineering and bioreactor development, and gene repair in CNS injury. [unreadable] [unreadable] [unreadable]