E2270. MRI of Pediatric Epilepsy: A Pictorial Review
  1. Claudia Cabarcas; Universidad del Norte
  2. Miguel Aranda Hernandez; Universidad Nacional de Colombia
  3. Luz Moreno Gomez; Universidad Nacional de Colombia
Approximately 50 million people worldwide have epilepsy, making it one of the most common neurological diseases worldwide. MRI is the study of choice for the identification of anomalies with epileptogenic potential. The evaluation of these studies by experts has a sensitivity of up to 50% increasing up to 91% when adequate protocols are performed. The aim of this academic exhibit is to discuss the main structural pathologies in patients with epilepsy (including updates in nomenclature and classifications), imaging indications, MRI protocol, principles for structured MRI evaluation, and supplying a guideline for the approach to imaging studies.

Educational Goals / Teaching Points
Analyze the utility of magnetic resonance for the study of pediatric patients with difficult-to-manage epilepsy. Review the principles for structured MRI approach focused on the detection of epilepsy-associated lesions. Recognize the most important imaging findings in the different etiologies of epilepsy in pediatric population. Discuss the most important imaging findings in congenital and acquired entities, including cortical development malformations and vascular entities. Recognize the imaging characteristics of brain neoplasms most frequently associated with epilepsy.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The objective of imaging in the context of epilepsy is to identify structural alterations that act as epileptogenic foci, and thus, establish the best management for each patient. Magnetic resonance imaging is the study of choice for the diagnosis of anomalies with epileptogenic potential; findings may vary between the different lesions, for which it is imperative to know the imaging characteristics of each of the entities involved. Within the etiologies associated with epilepsy, focal cortical dysplasia is the most common diagnosis among children, followed to a lesser extent by hippocampal sclerosis, which is the most common histopathological diagnosis among adults. Tumors are the second most common cause in both groups. Other less prevalent causes can be divided into congenital, sequel, vascular, neurocutaneous disorders, and others. A systematic evaluation of the images increases the possibility of detecting lesions with epileptogenic potential. For example, T1IR and FLAIR sequences with isotropic voxel size show clear gray-white matter differentiation thus allowing for identification of subtle malformations of cortical development.

MRI is the most valuable imaging tool to approach pediatric patients presenting with epilepsy resistant to pharmacological management. Many underlying causes such as congenital abnormalities, neoplasms or vascular malformations can be adequately characterized by this method. Radiologists working in a pediatric hospital setting should be familiar with these entities and with basic MRI protocol to provide adequate diagnoses to patients with epileptic manifestations. It is important for radiologist to recognize brain neoplasms associated with epilepsies since they tend to be low-grade, favorable prognosis tumor and with positive postsurgical outcomes.