7T Epilepsy Task Force Consensus Recommendations on the Use of 7T MRI in Clinical Practice
Giske Opheim, Anja G. van der Kolk, Karin Markenroth Bloch, Albert Colon, Kathryn A. Davis, Thomas R. Henry, Jacobus F.A. Jansen, Stephen E. Jones, Jullie W. Pan, Karl Rössler, Joel M. Stein, Maria Strandberg, Siegfried Trattnig, Pierre‐François Van de Moortele, María Isabel Vargas, Irène Wang, Fabrice Bartoloméi, Neda Bernasconi, Andrea Bernasconi, Boris C. Bernhardt, Isabella M. Björkman‐Burtscher, Mirco Cosottini, Sandhitsu R. Das, Lucie Hertz‐Pannier, Sara K. Inati, Michael T. Jurkiewicz, Ali R. Khan, Shuli Liang, Ruoyun Emily, Srinivasan Mukundan, Heath Pardoe, Lars H. Pinborg, Jon̈athan R. Polimeni, Jean‐Philippe Ranjeva, Esther Steijvers, Steven M. Stufflebeam, Tim J. Veersema, Alexandre Vignaud, Natalie Voets, Serge Vulliémoz, Christopher J. Wiggins, Rong Xue, Renzo Guerrini, Maxime Guye
Abstract
Identifying a structural brain lesion on MRI has important implications in epilepsy and is the most important factor that correlates with seizure freedom after surgery in patients with drug-resistant focal onset epilepsy. However, at conventional magnetic field strengths (1.5 and 3T), only approximately 60%–85% of MRI examinations reveal such lesions. Over the last decade, studies have demonstrated the added value of 7T MRI in patients with and without known epileptogenic lesions from 1.5 and/or 3T. However, translation of 7T MRI to clinical practice is still challenging, particularly in centers new to 7T, and there is a need for practical recommendations on targeted use of 7T MRI in the clinical management of patients with epilepsy. The 7T Epilepsy Task Force—an international group representing 21 7T MRI centers with experience from scanning over 2,000 patients with epilepsy—would hereby like to share its experience with the neurology community regarding the appropriate clinical indications, patient selection and preparation, acquisition protocols and setup, technical challenges, and radiologic guidelines for 7T MRI in patients with epilepsy. This article mainly addresses structural imaging; in addition, it presents multiple nonstructural MRI techniques that benefit from 7T and hold promise as future directions in epilepsy. Answering to the increased availability of 7T MRI as an approved tool for diagnostic purposes, this article aims to provide guidance on clinical 7T MRI epilepsy management by giving recommendations on referral, suitable 7T MRI protocols, and image interpretation. DNET= : dysembryoplastic neuroepithelial tumor; DRFE= : drug-resistant focal epilepsy; FCD= : focal cortical dysplasia; FLAIR= : fluid-attenuated inversion recovery; FWMS= : fluid and white matter suppressed; GRE= : gradient-recalled echo; HS= : hippocampal sclerosis; LEAT= : long-term epilepsy-associated tumor; MCD= : malformations of cortical development; MPRAGE= : magnetization-prepared rapid acquisition gradient echo; MRS= : magnetic resonance spectroscopy; RF= : radiofrequency; SNR= : signal-to-noise ratio; SWAN= : susceptibility-weighted angiography; SWI= : susceptibility-weighted imaging; TLE= : temporal lobe epilepsy; TSE= : turbo spin echo; UHF= : ultrahigh field