Upgrade of 7T MRI Research System

DESCRIPTION (provided by applicant): This application proposes to upgrade the gradients and electronics of a 7 Tesla small animal magnetic resonance imaging (MRI) and spectroscopy (MRS) system located in the bioimaging core facility at the University of Nebraska Medical Center (UNMC). The present system is used for 16 NIH-funded projects including two program projects and a nanomedicine COBRE, and is supported by a Core Support P30 grant. Currently funded projects use an average of 20 hours per week of MRI system time per scanner which represents 80% of the current system use. The proposed upgrade will enhance the quality and throughput of imaging studies for a wide range of projects, including neuroimaging, spectroscopy, and cell- and nanoparticle-tracking studies in the neurosciences and in nanotechnology development. Nanotechnology projects include development of drug delivery platforms for antiretroviral, anti-inflammatory, neuroprotective, and anti-cancer medications. The system to be upgraded is a Bruker Biospec 7T/21cm system installed in 2001. Because of the age of the system's hardware, current and future operating system software releases are no longer compatible. Thus, the upgrades proposed here will serve three important functions. First, the proposed hardware upgrade will improve signal to noise, gradient performance, and system stability, improvements that will be particularly useful for spectroscopic studies used for MRI assessment of neurological dysfunction and disease. Second, enhanced digitizer speed and the associated software update will allow short and zero echo time imaging, a technique that provides robust positive contrast for super paramagnetic iron oxide (SPIO) tracer studies. Zero echo time imaging combined with T2* weighted imaging will make possible the development of automated detection algorithms for cell and nanoparticle biodistribution studies via the correlated positive and negative signal intensity changes that occur in the presence of SPIO. Third, the upgrades will include a multichannel receiver and coil to take advantage of "parallel imaging" methods available in the newer software releases. This feature will significantly improve the quality and spatial fidelity of single shot imaging techniques, improving diffusion tensor imaging and allowing the migration of relaxivity and perfusion mapping techniques to echo planar or spiral imaging based single shot methods. Public Health Relevance: Imaging-based disease detection methods and new therapies for brain diseases, rheumatoid arthritis, and cancer using nanoparticle drug delivery are being developed at the University of Nebraska Medical Center. A critical link in the development of these new drug delivery methods is the ability to track their distribution and therapeutic effectiveness non-invasively using imaging methods first in animal models of disease and then in humans. This application proposes to upgrade an MRI scanner to current standards, allowing efficient and clinically relevant imaging methods to be employed while studying small animal models of disease for development of drug delivery nanoparticles.