BIG fMRS - Multi-Site reproducibility of Functional MRS

Functional magnetic resonance spectroscopy (fMRS) broadly describes dynamic changes in cerebral metabolites in response to external stimuli or cognitive or physiological state-manipulation. FMRS is the only method that safely and non-invasively measures differences in cellular metabolism and neurotransmission during activation in the human brain. Reproducibility of fMRS results is confounded by heterogeneous experimental methods at several levels, in the MRS acquisition, the experimental design and in data analysis. This reduces the comparability of studies and limits the broader uptake of the method in basic and clinical neuroimaging. In the international collaborative project “Big fMRS”, we aim to establish the main sources of variability of fMRS acquisition and quantification, focusing on stimulus-derived glutamate response. We seek international collaborators to include in the big fMRS study to increase the diversity and ultimately the quality of the research, and to create a multi-site study. The collaborators are requested to acquire a dataset using either 1) predefined, mutually-agreed, and standardised parameters consistent across all participating laboratories (i.e. in terms of sequence and experimental paradigm) or 2) a fixed experimental paradigm, but with their own optimised acquisition scheme. The overall objectives of this work are: 1) to evaluate if reported fMRS measured increases in glutamate in response to neural activity are reproducible across multiple sites; 2) to provide an openly available dataset, and analysis pipelines for researchers; 3) to publish an extensive description of the collective dataset in a peer-reviewed journal; and 4) to create a standardised fMRS protocol. This will enable a better understanding of the sources of variability in the fMRS signal, and, ultimately, make fMRS a more reliable and useful tool for neuroscience research.