Enhanced Detection of Epileptogenic Zone Using Prisma 3T MRI in Patients with MRI-negative Focal Epilepsy

Long-term seizure freedom in patients with medically refractory focal epilepsy (MRFE) is more likely when the seizure-onset zone corresponds to a magnetic resonance imaging (MRI) detectable lesion. Thus, advances in brain imaging are highly therapeutically relevant. The Prisma 3 Tesla (T) MRI leverages improved signal-to-noise ratio and enhanced image resolution with decreased artifact compared to conventional 3T MRI. However, the use of this MRI technique to improve the quality of presurgical evaluation in epilepsy has not been evaluated. In the present study, we evaluated the utility of Prisma 3T MRI to enhance the detection of brain lesions in patients with MRFE.

Patients with MRFE who were at least 19 years old and underwent Prisma 3T MRI in addition to conventional 3T MRI were identified. Those without an identifiable seizure etiology based on prior conventional 3T MRI or who had discordant scalp electroencephalography (EEG) and MRI findings were included. All patients underwent imaging via Prisma 3T MRI using a standardized protocol.

Of 24 patients, 6 (25%) had previously undiscovered abnormalities found on Prisma 3T MRI, including focal cortical dysplasia, mesial temporal sclerosis, pulvinar lesion, and other lesions. Three patients (12.5%) with new findings on Prisma 3T MRI were able to achieve complete seizure freedom following surgical intervention.

The addition of Prisma 3T MRI in the presurgical assessment of MRFE helps to uncover clinically significant abnormalities previously missed on conventional 3T MRI. This innovation may facilitate hypothesis generation for intracranial EEG implantation and streamline the presurgical evaluation.