SMALL ANIMAL CANCER IMAGING (SACI) SHARED RESOURCE: PROJECT SUMMARY With the revolution in molecular biology, transgenic animal models – in particular mice – have become an indispensable part of the cancer research armamentarium. The Siteman Cancer Center’s (SCC) Small Animal Cancer Imaging (SACI) Shared Resource (SR) (initially established under the auspices of the NCI’s Small Animal Imaging Resource Program) addresses the need for nondestructive imaging and analysis of small animal laboratory models of cancer. It provides state-of-the-art facilities and infrastructure for magnetic resonance imaging, positron emission tomography, X-ray computed tomography, single-photon emission computed tomography, and optical (including Cerenkov) imaging of mice, rats, and other small laboratory animals that serve as models of cancer. SACI combines instrumental and intellectual capabilities found at few other institutions and serves a broad community of cancer scientists who have a pressing need for quantitative image analysis of small animal model systems. The principal functions of SACI are to provide SCC members: i) access to, and maintenance of, small animal magnetic resonance, nuclear medicine, and optical imaging scanners for cancer research; ii) technology expertise and consultation in study design, protocol development, and data analysis/interpretation. In addition to supporting cancer research applications of small animal imaging, SACI also provides research and development at the frontier of imaging technology in an effort to make the most powerful new imaging strategies available to its community of users. The SR is organized around three modality-specific imaging components: (i) nuclear medicine, (ii) magnetic resonance, and (iii) optical. An overarching goal is translation to the clinic of imaging protocols and therapeutic agents developed and validated with small animal models. Thus, SACI directly supports the mission of the SCC by supporting basic discovery cancer research and cancer imaging protocols with translational potential.