Proton magnetic resonance spectroscopy (1H MRS) enables non-invasive biochemical sampling of tissues, potentially aiding diagnosis, prognosis and monitoring of various pathologies, while providing novel imaging biomarkers. Ultra-high-field (UHF) imaging at 7 tesla (7T) benefits from improved spectral dispersion due to an increase in chemical shift differences between metabolites, and a higher signal-to-noise ratio (SNR), making 1H MRS at 7T a particularly promising diagnostic tool for identifying and separating metabolites not clearly resolved at lower field strengths. However, 1H MRS at UHF presents technical challenges related to the short RF wavelength at 7T, resulting in B1 transmit field inhomogeneity, and the increased magnetic susceptibility gradients leading to B0 field inhomogeneity. Appropriate MRS methods are required to address these issues. In this article, we describe the technical aspects and challenges of 1H MRS at 7T, based on the experience in our centre, where single voxel 1H MRS has featured prominently in clinical 7T research applications for several years. We present data from six patients with glial tumours, including three who were post-operative, in whom post-surgical metalware affects the specific absorption rate (SAR), along with two patients with neuroinflammatory conditions and two with neurodegenerative diseases. The potential clinical use of 1H MRS for these pathologies and its possible integration as a promising biomarker into advanced imaging pathways are discussed.
Keith et al. (Wed,) studied this question.