Brain mapping: its use in patients with neurological disorders.

Using imaging to study disorders of the brain is a process that is now almost a century old. The most rapid advances and the greatest number of new techniques have been developed in the last thirty years. These methods provide previously unavailable insights into the mechanism of disease, diagnostic information for patients as well as an objective and noninvasive way of planning and monitoring therapy. The overall strategy for using these methods is discussed in this review along with illustrative highlights of three techniques: diffusion and perfusion magnetic resonance imaging, helical X-ray computed tomography and optical intrinsic signal imaging. While new techniques provide different perspectives about brain physiology and pathophysiology, advanced analytic methods for all techniques, new and old, have demonstrated their ability to extract more information from these methods than simple qualitative analysis can provide. Strategies for developing large population, probabilistically-based references and atlases are discussed along with disease-specific atlases of use in studying the natural history of a disorders, therapeutic interventions and strategies for monitoring clinical trials of new therapeutic agents. The integration of information across modalities, spatial and temporal scales, subjects and clinical trials should provide an effective way of providing more comprehensive insights into the mechanisms of disorders that effect the human nervous system, both improving diagnostics and the planning and monitoring of therapeutics.