Background and purpose: Surgery is the first choice therapeutic approach in case of drug-resistant epilepsy. Unfortunately, up to 43% of patients referred for presurgical assessment do not have a lesion detectable by routine 3T magnetic resonance imaging (MRI) (MRI-negative), although most of them likely have an underlying epileptogenic lesion. Thus, new MRI modalities with increased sensibility for epileptogenic lesions are required. This paper describes the magnetization-prepared two rapid acquisition gradient echoes (MP2RAGE) and susceptibility-weighted imaging (SWI) findings at 7T in a series of patients with drug-resistant epilepsy of different etiologies.
Methods: Prospective pilot study of 7 patients with drug-resistant lesional epilepsy and absence of contraindications for MRI underwent a research 7T head-only scanner. Qualitative analysis of the high-resolution MP2RAGE and SWI sequences is given for each case. This study was approved by the local ethics committee. Written informed consent was obtained from each participant.
Results: This study shows that such sequences at ultra-high field are new and valuable approaches to unravel and characterize epileptogenic lesions. Particularly, MP2RAGE shows a better delineation of lesions due to high gray-white matter contrast and structural resolution, and SWI reveals new imaging signs related to improved magnitude and phase contrast imaging.
Conclusion: MRI at ultra-high field is very promising for the detection of inconspicuous epileptogenic lesions and may facilitate epilepsy surgery of a great number of to-date MRI-negative patients.
Keywords: Ultra-high-field MRI; focal epilepsy; magnetization-prepared two rapid acquisition gradient echoes (MP2RAGE); susceptibility-weighted imaging (SWI).
Copyright © 2018 by the American Society of Neuroimaging.