Test-retest reliability of myelin volume fraction quantified with multicomponent MPnRAGE

Motivation: There is a need for rapid and high-resolution myelin water imaging techniques, while high test-retest reliability is necessary for widespread adoption. Goal(s): Evaluate the repeatability of multicomponent relaxometry with MPnRAGE. Approach: Data from 12 adolescent subjects scanned 3 consecutive times were reconstructed with motion-correction and fit to multicomponent MPnRAGE model. Coefficient of variation (CoV) was calculated across the 3 scans for each subject for several white and gray matter regions. Results: Mean CoV was <7% across white matter regions. Myelin volume fraction trends between regions were also consistent with prior T2-based techniques. Impact: A recently developed T1-based technique for myelin water imaging with MPnRAGE demonstrates high repeatability across consecutive scans. Multicomponent relaxometry with MPnRAGE enables high-resolution and motion-corrected myelin mapping in under 10 minutes of scan time.