Abstract
The traditional approach for measuring myelin-associated water with quantitative magnetic resonance imaging (MRI) uses multi-echo T 2 relaxation data to calculate the myelin water fraction (MWF). A fundamentally different approach, abbreviated “mcDESPOT”, uses a more efficient steady-state acquisition to generate an equivalent metric (f M). Although previous studies have demonstrated inherent instability and bias in the complex mcDESPOT analysis procedure, f M has often been used as a surrogate for MWF. We produced and compared multivariate atlases of MWF and f M in healthy human brain and cervical spinal cord (available online) and compared their ability to detect multiple sclerosis pathology. A significant bias was found in all regions (p < 10 –5), albeit reversed for spinal cord (f M-MWF = − 3.4%) compared to brain (+ 6.2%). MWF and f M followed an approximately linear relationship for regions with MWF < ~ 10%. For MWF > ~ 10%, the relationship broke down and f M no longer increased in tandem with MWF. For multiple sclerosis patients, MWF and f M Z score maps showed overlapping areas of low Z score and similar trends between patients and brain regions, although those of f M generally had greater spatial extent and magnitude of severity. These results will guide future choice of myelin-sensitive quantitative MRI and improve interpretation of studies using either myelin imaging approach.
Original language | English |
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Article number | 1369 |
Pages (from-to) | 1369 |
Journal | Scientific Reports |
Volume | 11 |
Issue number | 1 |
DOIs | |
Publication status | Published - 14 Jan 2021 |