Multimodality imaging systems such as PET-CT and PET-MRI provide valuable anatomic as well as metabolic information about tissue and have become standards-of-care in certain clinical settings. e synergistic combination of high spatial resolution with rich functional information oers improved clinical decision-making and disease management because of increased understanding of the characteristics and progression of disease. An emerging and potentially promising multimodality technology combines near-infrared spectroscopic (NIRS) imaging with MRI. NIRS provides data on the functional status of tissue, including its hemoglobin, oxygen saturation, water, and lipid concentrations. Dierences in these parameters are oen signatures of malignant tissue; thus, including NIRS with MRI can augment identication of the boundaries of disease with indicators of its aggressiveness. Combined NIRS and MR imaging is a technique in which MRI signicantly improves the accuracy of the NIRS results and NIRS signicantly improves the specicity of MRI for diagnosis of disease such as breast cancer.