Advanced magnetic resonance imaging techniques to evaluate CNS glioma.

To make full use of the benefits of magnetic resonance imaging (MRI) in the evaluation of intracranial glioma, a variety of advanced MRI and qualitative and quantitative techniques can be added to the radiologists' diagnostic armamentarium, beyond the standard contrast-enhanced images. These techniques include perfusion MRI, which is useful in the characterization of glioma because a relative quantification of cerebral microcirculatory parameters may be estimated; magnetic resonance spectroscopy, which can provide an estimate of the concentration of normal and abnormal metabolites in the brain and, when supplemented with magnetic resonance perfusion data, can be a useful tool for distinguishing between tumor recurrence and radiation necrosis; and diffusion tensor imaging, which combines physiologic behaviors unique to the cytoarchitecture of brain cells and the interstitial tissues with 2D and 3D anatomic magnetic resonance images, and thereby differentiates intact white matter tracts, displaced by tumor or surrounding edema, from invasion or disruption by a more aggressive neoplasm.