Quantitative imaging and image-guided interventions are a leading force in a new era of precision medicine where quantitative methods of engineering and systems sciences have a pivotal role in the detection, diagnostics, and treatment of various diseases. There are urgent needs to develop quantitative imaging methods and bioengineering tools for aiding clinical decision making. Such quantitative imaging may require the use of multiple imaging modalities that provide anatomical, functional, and molecular information at the cellular and molecular levels. This talk will illustrate the power of multimodality imaging and image-guided intervention (IGI) technology for cancer detection and diagnosis. A successful example will be provided to demonstrate how innovative tools of biomedical engineering can be translated to the clinic setting in order to save lives and improve patient care. Specifically, this research developed quantitative imaging and IGI technologies, including PET molecular imaging, deformable image registration, automatic image segmentation, and computer assisted intervention, for improved the detection and diagnosis of prostate cancer in human patients. By combining multimodality imaging, multidimensional data, and IGI technologies, this research is to have positive implications for cancer detection, diagnosis, and therapy.