Purpose To discuss the MRI indications, protocol and findings used to delineate between congenital malformations, posttraumatic epilepsy, tumoral lesions, vascular lesions, mesial temporal sclerosis and others types of epileptogenic lesions; to illustrate the most common epileptogenic brain lesions in paediatric population.

Material and method Retrospective study, of paediatric patients with partial or generalised sesizures explored in our department by MRI, in the last 10 years. We have used a specific MRI protocol which provides high spatial resolution, with a very good grey matter and white matter contrast (3D T1 IR), a high contrast resolution images of the hippocampus (T2 IR, 3D FLAIR) and sequences sensitive to magnetic susceptibility (SWI, T2*). Intravenous contrast administration (0,1 ml/Kgc of Gd-BOPTA) was used only used in specific clinical situations (such in neoplasia or in meningitis). In particular cases, MR angiography sequences- 3D TOF and 2D TOF were necessary to evaluate the morphology of intracerebral arterial vessels or venous structures.

Results We will discuss and illustrate MRI features found in mesial temporal sclerosis, focal and diffuse developmental brain abnormalities, epileptogenic tumours (such as ganglioglioma, DNET, hypothalamic hamartoma), neurocutaneous syndromes, granulomas, vascular malformations, hypoxic ischaemic encephalopathy, gliosis, and miscellaneous.

Conclusion MRI represent the best imaging modality to detect the structural epileptogenic lesions and the relationship between lesion and the adjacent brain structures, and also to make an etiologic diagnosis.