Related Experiment Video
Updated: May 16, 2025
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Age-related changes in myelin and myelin water quantified with short-TR adiabatic inversion-recovery (STAIR)
James Lo1, Jiaji Wang2, Dylan Tran2
1Department of Radiology, University of California, San Diego, CA, USA; Department of Bioengineering, University of California, San Diego, CA, USA.
Abstract:
Myelin proton density fraction (MPDF) and myelin water fraction (MWF) measured with short-TR adiabatic inversion-recovery (STAIR) sequences are potential biomarkers of aging and neurodegeneration, but the effects of aging on MPDF/MWF remain unknown. This study aims to assess relationships between age and MPDF/MWF using the 3D STAIR ultrashort echo time (STAIR-UTE) and STAIR short echo time (STAIR-STE) sequences, respectively. 42 volunteers (29 young (<55y), 13 old (>55y)), were recruited for MPDF and MWF mapping for white matter (WM) and gray matter (GM) on a 3 T scanner. Excellent inter-reader reliability was demonstrated for MPDF and MWF measurements with ICC values of 0.97 and 0.98, respectively, between two readers. In the young group, WM MPDF and MWF range from 8-13 % and 6-13 %, respectively, while GM MPDF and MWF range from 5-7 % and 3-5 %, respectively. In the old group, WM MPDF and MWF range from 6-12 % and 5-13 %, and GM MPDF and MWF range from 3-6 % and 2-5 %, respectively. The young group's MPDF/MWF values were significantly higher than those of the old group. Altogether, the 42 volunteers display linear and quadratic associations of MPDF/MWF with age. MPDF demonstrated significant correlations with MWF in the majority of brain regions. This study demonstrates the capability of two myelin imaging biomarkers, STAIR-UTE measured MPDF and STAIR-STE measured MWF to map brain myelin and MW. These biomarkers hold the potential to differentiate normal aging from neuroinflammatory/neurodegenerative diseases.
Insights
Myelin imaging biomarkers, myelin proton density fraction (MPDF) and myelin water fraction (MWF), decrease with age. These markers show potential for distinguishing normal aging from neurodegenerative diseases.
Area of Science:
- Neuroimaging
- Biomarkers
- Aging Research
Background:
- Myelin proton density fraction (MPDF) and myelin water fraction (MWF) are potential biomarkers for aging and neurodegeneration.
- The impact of aging on MPDF and MWF is not well understood.
Purpose of the Study:
- To investigate the relationship between age and MPDF/MWF using specific MRI sequences.
- To assess the utility of these myelin imaging biomarkers in differentiating aging effects.
Main Methods:
- Recruited 42 volunteers (29 young, 13 old) for MPDF and MWF mapping using 3D STAIR ultrashort echo time (STAIR-UTE) and STAIR short echo time (STAIR-STE) sequences.
- Measured MPDF and MWF in white matter (WM) and gray matter (GM) on a 3T scanner.
- Analyzed inter-reader reliability, demonstrating excellent agreement (ICC > 0.97).
Main Results:
- MPDF and MWF values were significantly higher in the younger group compared to the older group.
- Both linear and quadratic associations between MPDF/MWF and age were observed across all volunteers.
- MPDF showed significant correlations with MWF in most brain regions.
Conclusions:
- The study successfully mapped brain myelin using STAIR-UTE measured MPDF and STAIR-STE measured MWF.
- These myelin imaging biomarkers can detect age-related changes in myelin.
- MPDF and MWF show promise for differentiating normal aging from neuroinflammatory or neurodegenerative conditions.
