Magnetic resonance: a multimodal approach to the brain?

Magnetic resonance of the brain offers the unique possibility of acquisition of morphological data in high resolution quality, analysis of metabolic disturbances, and the assessment of brain function. Basic principle is the BOLD effect, using the difference of the magnetic moments of oxy- and deoxyhemoglobin as intrinsic mechanism of contrast. Still the optimum techniques for functional imaging are not established: echo planar imaging requires a very costly hardware, whereas gradient echo imaging is feasible on clinical routine MR scanners. Although many experimental studies have been published on visual, motor, and auditory paradigms, clinical applications have not been established up to now. Analysis of epileptogenic foci combining high resolution imaging and functional information seems very promising as well as preoperative determination of critical areas in neurosurgery.