The long-term objective of the application under consideration, a competing renewal of our Program Project in MR-guided Therapy, is to provide the scientific, medical, and technical infrastructure for the development of interventional and intraoperative MRI for the treatment of brain and prostate cancer. This Program Project combines several technological advances related to the use of high field MRI with an advanced imaging platform. In parallel, this proposal addresses issues related to limited access to the patient in the closed bore magnet. The goal is to move most of the procedures (open surgeries, thermal ablations) to the advanced 3Tesla imaging platform to achieve a faster and more flexible image acquisition which, in turn, will provide improved localization, targeting, monitoring and therapy control for those procedures that can be adapted to this new application environment. To this end, we will undertake the following research initiatives: Project 1: develop computational methods that account for anatomical changes during neurosurgical intervention and optimize the frequency of serial imaging;Project 2: build an image-guided and controlled therapy delivery system for the non-invasive destruction of prostate cancer with MRI-controlled focused ultrasound;Project 3: provide image-control for manipulators and robotic devices that enhances the manual capacity of physicians and facilitates procedures in a closed bore magnet;Project 4: develop novel imaging platforms and methods for enhanced parallel MRI data acquisition applicable to image-guidance;and Project 5: create an integrated image-based system to allow MR-guided targeted interventions for the treatment of prostate cancer. These five projects will work synergistically to not only develop better imaging methods for defining the cancers, but will also work to facilitate the improved, targeted treatment of brain tumors and prostate cancer.