Lenka Vaculčiaková | Improvements in mapping of cortical myelination using quantitative MRI

Quantitative MRI offers the potential to characterize human brain microstructure. Mapping of several MR parameters can be efficiently done using the multi-parameter mapping (MPM) protocol, which allows for quantification of PD, R2*, R1 and MT contrasts, reflecting respectively water content, iron concentration, myelin and macromolecular content. Even small improvements in the reliability of parameter maps are relevant in the context of quantifying myelination changes (for example in disease), which are typically in the order of a couple of percent. Therefore, we investigated correction of physiological artifacts caused by breathing and head motion, which are especially prominent at 7T and in long high resolution acquisitions, and applied the corrections in an elderly cohort including Alzheimer patients. Additionally, we modified the MPM protocol to measure an inhomogenous MT (ihMT) metric that has been shown to have higher specificity to myelin than simple MT contrast, and optimized the measurement protocol at our 3T scanners.