Intraaxial brain masses are a significant health problem and present several imaging challenges. The role of imaging is no longer limited to merely providing anatomic details. Sophisticated magnetic resonance (MR) imaging techniques allow insight into such processes as the freedom of water molecule movement, the microvascular integrity and hemodynamic characteristics, and the chemical makeup of certain compounds of masses. The role of the most commonly used advanced MR imaging techniques-perfusion imaging, diffusion-weighted imaging, and MR spectroscopy-in the diagnosis and classification of the most common intraaxial brain tumors in adults is explored. These lesions include primary neoplasms (high- and low-grade), secondary (meta-static) neoplasms, lymphoma, tumefactive demyelinating lesions, abscesses, and encephalitis. Application of a diagnostic algorithm that integrates advanced MR imaging features with conventional MR imaging findings may help the practicing radiologist make a more specific diagnosis for an intraaxial tumor.
(c) RSNA, 2006.