Development of a post-processing pipeline for Myelin Water Imaging at 7 T

Abstract: Myelin water imaging, MWI, is a non-invasive method used for quantifying the amount of myelin in the brain that can aid the understanding of brain plasticity and neurodegenerative diseases, such as Multiple Sclerosis (MS). Conventional MWI is done at a field strength of 3 T, though there are indications that higher field strength may lead to higher resolution images. We investigate the use of isotropic voxels and echo time (TE) 8 ms at 7 T MWI, establish favorable parameters, and compare our results with a previous study, where anisotropic voxels and TE 10 ms were used. Moreover, we aim to demonstrate the usefulness of MWI at 7 T and further develop it by looking at a pilot data set consisting of diagnosed MS patients and comparing our results to an extensive 3 T MWI atlas. Healthy individuals were scanned using 8 ms and 10 ms TE, along with a pilot dataset consisting of scans from MS patients using 8 ms TE at 7 T. We have demonstrated that MWI on 7 T scans with isotropic voxels and an 8 ms TE can be used to identify lesions associated with MS. Although 8 ms TE performed equally well as the established 10 ms TE when it comes to the characterization of the myelin water fraction, there is not enough evidence to validate that an 8 ms TE is superior to 10 ms. Further research is warranted to evaluate the possibility of generalizing the 3 T MWI atlas across field strengths.