Replacement of PET and MRI Scanners for Small Animal Imaging - Summary / Abstract This is an application for funding to purchase a new, integrated MRI-PET scanner for animals that will replace two obsolete, separate systems, an MRI and a microPET scanner. Our 4.7T Varian/Agilent MRI scanner has been in continuous use for 19+ years, while our Siemens Inveon PET scanner is >11 years old. The current electronics and console of the Varian MRI are no longer state-of-the-art, their limited capabilities are affecting productivity, and the system is no longer supported by the manufacturer (Varian/Agilent). The PET system would replace an obsolete Siemens Inveon PET/CT scanner that is also no longer supported by the manufacturer and which is highly unreliable in use and can no longer perform CT imaging. For both systems there have been no software upgrades for several years, replacement parts are scarce as the vendors are no longer in the animal scanner business, and overall the reliability and capabilities no longer meet the demands of our core users. The current 4.7T magnet would be replaced by a 7T magnet, with an accompanying gain in overall signal to noise ratio, greater spectral dispersion (e.g. for MRS and CEST), increased sensitivity to BOLD effects, and improved image quality. The new magnet would not use cryogens, so there would be considerable savings in operating expenses, and we would be insured against shortages of liquid helium. The PET insert would have an axial FOV of 80 mm, large enough to accommodate small, non-human primates and large rodents. The integrated scanner will be capable of simultaneous MRI and PET acquisitions, allowing new types of studies to be performed with accurate co-registration between modalities. PET studies will benefit from the availability of a large range of radiotracers obtainable from our research-dedicated cyclotron and radiochemistry laboratories. The device will be used by at least 22 established investigators, all of whom are already experienced users of animal imaging, in over 30 NIH-funded research applications and training programs. These research projects include applications in cardiac physiology; neuroscience (including studies of the architecture and functional organization of the brain and spine in non-human primates, as well as the actions of novel pharmaceuticals); cancer (including the study of tumor biology and treatment effects); lung disease (especially the detection of fibrosis); bone disorders; and basic imaging science. The projects of the 16 Major Users would require approximately 65% use of the availability of the instrument, the 6 Minor Users and two Center Core programs would require 16%, and the remaining time available would be used for exploratory research and new directions. The scanner will be housed and managed within the Vanderbilt University Institute of Imaging Science, and will be a primary research resource for a large number of experienced imaging scientists and trainees. The instrument will be supported by an established group of imaging experts and support staff. A comprehensive plan has been developed for the financial and technical support of the scanner as well as for its management, and the system is assured of strong institutional support and oversight.
