Abstract -- During last decade tremendous progress has been made in the development of medical imaging, image guided interventions, nanotechnology, molecular imaging probes and instrumentation. These new technologies have provided significant opportunities to advance medical practice and patient care. In this talk I will first present an overview of current practice of image guided interventions, in particularly image guided radiation therapy and recent technical developments in on-treatment volumetric image guidance. The need for molecular imaging and molecular image guidance will be highlighted. I will then talk about our recent research on high resolution and high sensitivity X-ray and radionuclide molecular imaging techniques, including X-ray luminescence computed tomography, X-ray fluorescence computed tomography, Cerenkov imaging and its potential application in image guided surgery.