Over the past decade, molecular imaging has emerged as the most important new direction in medical imaging research. This discipline is targeted at the use and development of new instrumentation, techniques, and probes for understanding the molecular and genetic basis of human biology and disease. With this proposal we seek to acquire a state-of-the-art Siemens (formerly Concorde Microsystems) hybrid microPET/microCAT QS scanner to support multiple projects that span the breadth of biomedical research and will greatly enhance molecular imaging research at UCSF. The microPET/CT will combine a high resolution PET with improved sensitivity and a high resolution CT to afford both functional and anatomical imaging without having to move the subject or transfer a bed between to independent scanners. UCSF, a world leader in biomedical research and medical imaging, has recently opened the Center for Molecular and Functional Imaging (CMFI). Significant resources have been committed to consolidate the Department of Radiology imaging research programs, site a cyclotron, provide the laboratory infrastructure and recruit key personnel to build a world class radiopharmaceutical development and imaging program. The microPET/CT is one of the key components that is critically needed to achieve the long term goals of the CMFI by providing an important molecular imaging tool for the UCSF research community. Seventeen research projects, largely supported by NIH funds, have been identified that will directly benefit from access to the microPET/CT. This systern will significantly enhance the molecular imaging research program by facilitating current research as well as enabling future NIH projects at UCSF and collaborating institutions within the greater San Francisco Bay Area. [unreadable] [unreadable] [unreadable]