The breadth and substance of anatomic (structural) and novel physiological (functional) imaging methods to noninvasively monitor and assess anticancer therapies continues to grow. Current techniques span several imaging disciplines including magnetic resonance (MR) imaging, positron emission tomography (PET), computed tomography (CT), ultrasound (US), and optical-based methods using fluorescence and bioluminescence techniques. These methodologies applied in the clinic and/or in animal models offer unique insights into disease processes. Applications affected by imaging include therapeutic response assessment, improved diagnostic evaluations, enhanced delineation of tumor boundaries, elucidation of the underlying mechanisms of therapeutic response and drug resistance, identification of high-risk subpopulations of transgenic animals with specific alterations in their genome leading to abnormal phenotypes, and prediction of therapeutic outcome. This chapter provides a brief introduction to this emerging field, focusing specifically on novel MR applications related to chemotherapeutic response assessment, step-by-step procedures to perform the outlined techniques, and algorithms to analyze resultant data.