title: 3T versus 1.5T phased-array MRI in the presurgical work-up of patients with partial epilepsy of uncertain focus.
abstract: OBJECTIVE
  To study 3T compared to 1.5T phased array magnetic resonance imaging (MRI) in the presurgical work-up of patients with epilepsy with complex focus localization.
  
  
  METHODS
  In all, 37 patients (>10 years) in preoperative work-up for epilepsy surgery were offered 3T in addition to 1.5T MRI if ambiguity existed about the epileptic focus. Scans were randomly reviewed by two observers, blinded for prior imaging, patient-identifying information, and each other's assessments, followed by a consensus meeting. The number of abnormal scans, detected lesions, and interobserver agreement were calculated and compared. The final consensus was compared to original scan reports.
  
  
  RESULTS
  One observer identified 22 lesions in both 3 and 1.5T scans, while the second identified more lesions in 1.5T scans (28 vs. 20). 3T MRI had better interobserver agreement. 3T revealed more dysplasias, while 1.5T revealed more tissue loss and mesial temporal sclerosis (MTS). The final consensus yielded 29 lesions, whereas original reports identified only 17 lesions.
  
  
  CONCLUSIONS
  The 3T scans revealed different lesions compared to 1.5T. Patients can benefit most from 3T scans when a dysplasia is suspected. Reevaluation by another experienced neuroradiologist is advised in case of negative or equivocal MRIs.
authors.affiliation: Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, The Netherlands. G.J.M.Zijlmans@umcutrecht.nl
authors.forename: Maeike
authors.initials: M
authors.lastname: Zijlmans
authors.forename: Gérard A P
authors.initials: GA
authors.lastname: de Kort
authors.forename: Theodore D
authors.initials: TD
authors.lastname: Witkamp
authors.forename: Geertjan M
authors.initials: GM
authors.lastname: Huiskamp
authors.forename: Jan-Henry
authors.initials: JH
authors.lastname: Seppenwoolde
authors.forename: Alexander C
authors.initials: AC
authors.lastname: van Huffelen
authors.forename: Frans S S
authors.initials: FS
authors.lastname: Leijten
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015588:Observer Variation; D018579:Patient Selection