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Abstract

Clinical Benefit of 3 Tesla Magnetic Resonance Imaging Rescanning in Patients With Focal Epilepsy and Negative 1.5 Tesla Magnetic Resonance Imaging

VOLUME 68 - NUMBER 3 / May - June (Original articles)

Lady D. Ladino, Section of Neurology, Hospital Pablo Tobón Uribe, University of Antioquia, Medellín, Colombia; Instituto de Alta Tecnología Médica (IATM), Medellín, Colombia; Division of Neurology, University of Saskatchewan, Saskatoon, Canada
Pedro Balaguera, Clínica Medellín, Medellín, Colombia
Simon Rascovsky, Instituto de Alta Tecnología Médica (IATM), Medellín, Colombia
Jorge Delgado, Instituto de Alta Tecnología Médica (IATM), Medellín, Colombia
Juan Llano, Instituto de Alta Tecnología Médica (IATM), Medellín, Colombia
Lizbeth Hernández-Ronquillo, Division of Neurology, University of Saskatchewan, Saskatoon, Canada
Bety Gómez-Arias, Hospital Universitario San Vicente Fundación, Medellín, Colombia
José F. Téllez-Zenteno, Division of Neurology, University of Saskatchewan, Saskatoon, Canada

Background: Magnetic resonance imaging is an essential tool in the pre-surgical evaluation of patients with drug-resistant epilepsy. Objective: Our aim was to assess the value of re-imaging patients with focal drug-resistant epilepsy. Methods: Thirty patients with negative or non-conclusive 1.5 Tesla magnetic resonance imaging were rescanned with 1.5T and 3T. All of them had previous 1.5 scans with no seizure protocol in a non-specialized center. Two neuroradiologists who were blinded to prior imaging results randomly reviewed the magnetic resonance images. Kappa score was used to assess the reliability. Results: Mean age of patients was 30 (SD ± 11) years. The intra-observer agreement for the first radiologist was 0.74 for 1.5T and 0.71 for 3T. In the second radiologist it was 0.82 and 0.66, respectively. Three lesions (10%) were identified by general radiologists in non-specialized centers using a 1.5T standard protocol. In our center a consensus between two neuroradiologists using epilepsy protocol identified seven lesions (23%) using 1.5T and 10 (33%) using 3T (p < 0.01). In 28% of patients this additional information resulted in a change in clinical management. Conclusions: 3T magnetic resonance imaging rescanning improves the diagnostic yield in patients with focal epilepsy and previous negative 1.5T magnetic resonance imaging. Use of 3T magnetic resonance imaging, epilepsy protocols, and interpretation by experienced neuroradiologists is highly recommended.

Keywords: Epilepsy surgery. Lesional epilepsy. Magnetic resonance imaging. Partial epilepsy. Refractory epilepsy. 3 Tesla.

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