Authors :
Presenting Author: Shimrit Uliel-Sibony, MD BSc – Tel Aviv Sourasky medical center
Edna Furman Haran, PhD – Weizmann Institute of Science
Rita Schmidt, PhD – Weizmann Institute of Science
Eiska Tegareh, BA – Weizmann Institute of Science
Moshe Amar, MSc – Weizmann Institute of Science
Natalie Oshri, BA – Weizmann Institute of Science
Lidor Bitan, MSc – Tel Aviv Sourasky medical center
Eli Heyman, MD – Shamir medical center
Jonathan Roth, MD – Tel Aviv Sourasky medical center
Orna Aizenstein, MD – Tel Aviv Sourasky medical center
Rationale:
To assess the diagnostic yield of 7T MRI in the detection of epileptogenic lesions in 3T MRI-negative adolescents with drug resistant focal epilepsy.
Methods:
Nine adolescents aged 13.7-16.8 (average 14.9) years, (5 males and 4 females) with refractory focal epilepsy and negative standard 3T MRI, underwent comprehensive multimodal presurgical assessment (VEEG, interictal PET scan with co-registration, EEG-fMRI and neuropsychological evaluation). Scans were performed on a 7 Tesla scanner (Siemens, MAGNETOM Terra). Scanning protocol comprised T1 weighted scans – magnetization-prepared rapid acquisition gradient echoes (MPRAGE), magnetization-prepared two rapid acquisition gradient echoes (MP2RAGE) (1) and fluid and white matter suppression (FLAWS) (acquired with WIP #925B, Siemens) (2), T2 weighted scans – TSE, SPACE and 3D FLAIR, and SWI (3). High resolution scans up to 0.45 mm3 were included. Neuroradiologist with expertise in epilepsy imaging inspected the 7T images unblended to the suspected epileptogenic location.
Results:
Suspicious epileptogenic lesions were identified in 3 patients, with retrospective identification of the lesion in 3T MRI in one patient. In 2/3 patients the lesion was consistent with the findings in all the modalities preformed in the preceded presurgical assessment. In one patient with identified lesion in 7T MRI, the PDG-PET was negative, though the VEEG, EEG-FMRI and neuropsychological evolution were concordant to the identified cortical lesion.Conclusions:
In focal refractory epilepsy, 7T MRI may potentially increase the ability to detect subtle cortical and subcortical structural lesion compared to previously negative MRI (at 3T). Our results show improved detection in at least a third of the patients. Surgical invasive monitoring is the next stage required to confirm the seizure onset zone.
Funding: No funding was received in support of this abstract.