Update on brain tumor imaging.

Brain tumor imaging has evolved from a strictly morphology-based discipline to one that encompasses function, physiology, and anatomy, enabled by advances in imaging and computer technology. This review outlines the current imaging standard for patients with brain tumors and summarizes the latest advances in physiology-based imaging methods that complement traditional brain tumor imaging protocol. Emphasis is placed on the strengths and limitations of the current imaging standards and on an overview of several advanced imaging methods, including diffusion-weighted magnetic resonance imaging, perfusion magnetic resonance imaging, and proton magnetic resonance spectroscopic imaging. Basic physical principles behind each imaging method are briefly presented, along with a more in-depth discussion of the clinical applications and potential pitfalls of each technique.