SUrface-PRojected FLuid-Attenuation-Inversion-Recovery Analysis: A Novel Tool for Advanced Imaging of Epilepsy

World Neurosurg. 2017 Feb:98:715-726.e1. doi: 10.1016/j.wneu.2016.11.100. Epub 2016 Nov 25.

Abstract

Objective: The objective of this pilot retrospective study is to describe the SUrface-PRojected FLuid-Attenuation-Inversion-Recovery (SUPR-FLAIR) analysis, a novel method mainly aimed at revealing cortical areas with subtle signal hyperintensity.

Methods: Images from 101 healthy controls and 10 patients suffering from drug-resistant partial epilepsy were retrospectively postprocessed. The brain surface was reconstructed from a 3-dimensional (3D) T1-weighted fast field echo (T1W-FFE) magnetic resonance imaging (MRI) scan. A turbo spin echo fluid attenuated inversion recovery axial scan was registered to the 3D T1W-FFE scan, and its intensity values were normalized. The cortical intensity signal was projected onto the brain surface, and surface-based analysis was performed, comparing each patient against the 101 controls. The localizations of the first positive lower P value cluster (PLPC) peak and the resection zone (RZ) were compared. We studied 5 patients with focal cortical dysplasia (3 of them with negative MRI) and 5 with hippocampal sclerosis.

Results: SUPR-FLAIR analysis localized the first PLPC peak in the RZ in all cases. Because all patients have been seizure free since surgery, it can be assumed that the epileptogenic zone (EZ) was included in the RZ. Therefore, SUPR-FLAIR analysis correctly aligned with the EZ, with 100% sensitivity.

Conclusions: SUPR-FLAIR analysis is a noninvasive technique that could be helpful for the definition of the EZ, especially when MRI is negative. Its use could reduce the indications for invasive electroencephalography or could provide essential data to refine the strategy of intracerebral electrode implantation in the most challenging cases.

Keywords: Epilepsy surgery; Epileptogenic zone; FLAIR intensity; Freesurfer; MRI-negative epilepsy; Postprocessing; SUPR-FLAIR; Stereoelectroencephalography; Surface-based analysis; Temporal lobe epilepsy.

Publication types

  • Technical Report

MeSH terms

  • Adolescent
  • Adult
  • Brain Diseases / complications
  • Brain Diseases / pathology
  • Brain Mapping / methods
  • Case-Control Studies
  • Child
  • Drug Resistance
  • Electroencephalography / methods
  • Epilepsy / etiology
  • Epilepsy / pathology*
  • Epilepsy / surgery
  • Female
  • Hippocampus / pathology
  • Humans
  • Imaging, Three-Dimensional
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Pilot Projects
  • Retrospective Studies
  • Sclerosis / complications
  • Sclerosis / pathology
  • Software
  • Young Adult