FIG 1.

Example multiparametric data acquired in a patient with breast cancer before and after one cycle of neoadjuvant chemotherapy. Diffusion-weighted magnetic resonance imaging (DW-MRI) returns estimates of the apparent diffusion coefficient (ADC), which can be used to provide estimates of cellularity. Dynamic contrast-enhanced MRI (DCE-MRI) provides estimates of tissue blood flow and permeability (K^trans), extracellular-extravascular volume fraction (v_e), and plasma volume fraction (v_p). [¹⁸F]Fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) provides estimates of the glucose standardized uptake value (SUV). These imaging measurements can be acquired noninvasively before, during, and after the start of therapy to characterize functional changes in tumor properties.