Plug-and-Play High-Order B0 Shimming for Reliable Temporal Lobe Epilepsy Magnetic Resonance Spectroscopic Imaging

Abstract: Epilepsy affects 7 million people globally, and the temporal lobe epilepsy (TLE) is its most common form. For TLE patients that are undergoing surgical treatment, functional neuroimaging is vitally important to localize epileptic focus, maximize the preservation of unaffected areas, and optimize post-surgical outcomes. MR spectroscopic imaging (MRSI) is a promising modality to directly localize abnormalities of metabolites and neurotransmitters in the epileptic focus. To date, multiple clinical studies have demonstrated the prognostic value of MRSI in post-surgical outcomes for TLE and other neurological disorders such as glioblastoma and brain trauma. However, the MRSI image reliability is often impaired by the insufficient B0 field homogeneity in a certain region of the brain. Particularly, the susceptibility mismatch between the air in the sphenoid sinus and temporal lobe(TL) leads to local B0 field distortion, hence disrupt the spectral quality in a major portion of the TL. Although state-of-the-art MRI scanners are equipped with B0 field correcting capability (B0 shimming), it can only correct for slow varying fields and not the higher-order field disturbance at the tissue/air interfaces. In order to provide accurate and reliable MRSI for the temporal lobe, a reliable high-order B0 shimming device that can fit into clinical workflow is highly desirable. There are limited options in the market of high-order B0 shimming devices. The available products are usually too heavy and too complicated to be adopted in a routine clinical setting. In this proposal, we propose a lightweight high-order shim coil that provides reliable whole TL MRSI coverage under standard clinical workflow. Adopting the surface shim/RF coil technology, lightweight coil components, and optimized interface design, a plug-and-play high-order B0 shim coil will be developed and integrated into a clinical high field scanner. The endpoints of this proposal will lay the foundation to enable clinical high-order B0 homogeneity in high field clinical scanners. This will facilitate the clinical translation of state-of-the-art MRSI for temporal lobe epilepsy and other major neurological diseases.