Radiology has become the mainstay for clinical diagnosis and together with pathology underpins clinical medicine. Imaging has come a long way from the revolutionary, but crude x‑rays of Roentgen at the turn of the 20th century to the exquisite temporal and spatial revolution offered by modern computed tomography, providing multislice (or 3D) sub-millimeter spatial and sub-second temporal resolution. Beyond x‑rays, MRI has revolutionized soft-tissue analysis by providing tissue contrast based on multiple parameters identified by varying repetition and echo times and gradients to reveal T1‑, T2‑, T2*‑, diffusion- and flow-weighted images. Nonetheless, the discipline hitherto remained essentially an anatomical analysis providing tumor location, size and spread. A new vision foresees prognostic radiology, whereby tumors are not only identified with high sensitivity and specificity, but there is stratification of tumors according to expected response to therapy, as well as early evaluation of therapeutic efficacy. Clinically, we are privileged to have a wide range of therapeutic choices, but this presents the challenge of selecting the right therapy. Societally, we are demanding greater efficacy at reduced cost. Increasingly, it has been realized that tumors that may outwardly appear quite similar may exhibit very different responses to therapy. As a result, there is increasing emphasis on tumor characterization using genomic, proteomic and metabolic techniques with the promise of assessing tumor aggressiveness and predicting response to therapy: generally, they require biopsy. A notable example is the evaluation of Her2‑neu expression for efficacy of Herceptin®. Noninvasive assessments are even more attractive.