title: 3-T intraoperative MRI (iMRI) for pediatric epilepsy surgery.
abstract: OBJECTIVE
  Three-tesla intraoperative MRI (iMRI) is a promising tool that could help confirm complete resections and disconnections in pediatric epilepsy surgery, leading to improved outcomes. However, a large proportion of epileptogenic pathologies in children are poorly defined on imaging, which brings into question the utility of iMRI for these cases. Our aim was to compare postoperative seizure outcomes between iMRI- and non-iMRI-based epilepsy surgeries.
  
  
  METHODS
  We performed a comparative retrospective analysis of non-iMRI- versus iMRI-based epilepsy surgeries with 2-year follow-up. Patients were stratified into well-defined cases (WDCs), poorly defined cases (PDCs), and diffuse hemispheric cases (DHCs). Primary outcomes were rates of complete seizure freedom and surgical complications. Secondary outcomes included good (Engel class I/II) seizure outcome, extent of resection/disconnection, and operative duration. Regression models were used to adjust for confounding.
  
  
  RESULTS
  Thirty-nine iMRI-based and 39 non-iMRI-based surgeries were included. The distributions of age, sex, and lesion class in each era were similar, but the distributions of individual pathologies varied. Seizure freedom and complication rates at 2-year follow-up were not different between the groups, but Engel class I/II outcome was more common in the iMRI group. Extent of resection/disconnection and length of surgery were similar in both groups. PDCs had the worst outcomes, which were unchanged by the use of iMRI.
  
  
  CONCLUSIONS
  Three-tesla iMRI-based epilepsy surgery may have the potential to improve patient outcomes. However, we conclude that iMRI, in its current state of use at our institute, does not improve outcomes for children undergoing epilepsy surgery. Given that its use appears safe, further research on this technology is warranted, particularly for the most challenging PDCs.
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Nebras M
authors.initials: NM
authors.lastname: Warsi
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada. oliver.lasry@mail.mcgill.ca.|Department of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine, McGill University, 1020 Pine Avenue West, Montréal, QC, H3A 1A2, Canada. oliver.lasry@mail.mcgill.ca.
authors.forename: Oliver
authors.identifier: http://orcid.org/0000-0001-9276-9658
authors.initials: O
authors.lastname: Lasry
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Adel
authors.initials: A
authors.lastname: Farah
authors.affiliation: Department of Medical Imaging, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Saint-Martin
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Montes
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Atkinson
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Farmer
authors.affiliation: Division of Neurosurgery, Department of Pediatric Surgery, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: Roy W R
authors.initials: RW
authors.lastname: Dudley
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D055815:Young Adult
keywords: Complications; Epilepsy; Imaging; Intraoperative MRI; Outcomes