Magnetic resonance imaging (MRI) is the radiological investigation of choic
e for the evaluation of patients with epilepsy. It is able to detect and ch
aracterize the structural origin of seizures, and significantly influences
treatment planning and prognosis. The indications for MRI, protocols used f
or MRI in epilepsy and the relevant imaging anatomy are discussed. The majo
r categories of epileptogenic lesions which result in chronic seizures are
reviewed and illustrated. Mesial temporal sclerosis is emphasized, reflecti
ng its major importance as a cause of medically intractable epilepsy. The r
ole of MRI in the planning and assessment of epilepsy surgery is considered
. (C) 2001 The Royal College of Radiologists.