Advanced MRI for Brain Metastases

Brain metastases are a common manifestation of metastatic tumors and occur in 20% to 40% of all cancer patients with significant implications regarding morbidity and mortality. This chapter focuses on magnetic resonance imaging (MRI) techniques, which are the current gold standard for imaging brain metastases and have been shown to be superior to other modalities, such as computed tomography (CT), for this purpose. While basic MRI techniques provide unparalleled tissue contrast that is essential in the brain, advanced MR techniques—including MR spectroscopy (MRS), chemical exchange saturation transfer (CEST), magnetization transfer (MT), perfusion imaging, diffusion-weighted imaging (DWI), hyperpolarized 13 C, and blood-oxygen-level-dependent (BOLD) MRI—provide the opportunity to explore important metabolic, functional, and micro-structural aspects of tumors. By manipulating various parameters, MR represents an extremely adaptable technique with essentially limitless opportunities for generating information on tumor biomarkers that can be used in the future to guide and direct management.