Identification of the epileptic focus: magnetic resonance imaging.

Magnetic resonance imaging (MRI) is the most sensitive and specific structural imaging technique available to demonstrate focal epileptogenic lesions in patients with intractable partial epilepsy. MRI may be useful in the selection of candidates for surgical treatment of epilepsy. The studies may also assist in the implantation of depth electrodes and in the stereotactic resection of epileptogenic lesions. More recent applications of this neuroimaging modality in the surgical treatment of epilepsy include pre-operative hippocampal formation of volume measurements and postoperative quantitative determinations of cortical resections.