The last decade has brought revolutionary new imaging techniques to cancer research. Along with accurate anatomical measurement techniques to detect and localize tumors, imaging methods based on quantifying physiologic and metabolic properties are also being developed. Molecular imaging has become a powerful tool for understanding the underlying biological processes governing tumor development and progression. In order to advance cancer research and exploit these technical advances in vivo imaging, in 2000 UCI established the Center for Functional Onco-Imaging (CFOI) which was later renamed after John Tu & Thomas Yuen in 2001 for their generous support. The long term goal of the center is to promote the application of imaging techniques in cancer research. Towards this aim, the development and application of imaging technologies are key research areas in our center. In addition to our centers’ research activities, we also serve as a campus resource, supporting the research of other investigators by providing expertise and facilities. The current imaging facilities at the center include: a 57-cm bore 3-Tesla MR system (humans), a combine MR-Diffuse Optical Tomography (MR-DOT) system (small animals), and a whole-body positron emission tomography (PET) system (humans). All combined multi-modality systems were developed in-house.