In:
Magnetic Resonance in Medicine, Wiley, Vol. 87, No. 5 ( 2022-05), p. 2329-2346
Abstract:
To investigate the long‐ and short‐T 1D components correlation with myelin content using inhomogeneous magnetization transfer (ihMT) high‐pass and band‐pass T 1D ‐filters and to compare ihMT, R 1 , and the macromolecular proton fraction (MPF) for myelin specific imaging. Methods The 3D ihMT rapid gradient echo (ihMTRAGE) sequences with increasing switching times (Δ t ) were used to derive ihMT high‐pass T 1D ‐filters with increasing T 1D cutoff values and an ihMT band‐pass T 1D ‐filter for components in the 100 µs to 1 ms range. 3D spoiled gradient echo quantitative MT (SPGR‐qMT) protocols were used to derive R 1 and MPF maps. The specificity of R 1 , MPF, and ihMT T 1D ‐filters was evaluated by comparison with two histological reference techniques for myelin imaging. Results The higher contribution of long‐T 1D s as compared to the short components as Δ t got longer led to an increase in the specificity to myelination. In contrast, focusing on the signal originating from a narrow range of short‐T 1D s ( 〈 1 ms) as isolated by the band‐pass T 1D ‐filter led to lower specificity. In addition, the significantly lower r 2 correlation coefficient of the band‐pass T 1D ‐filter suggests that the origin of short‐T 1D components is mostly associated with non‐myelin protons. Also, the important contribution of short‐T 1D s to the estimated MPF, explains its low specificity to myelination as compared to the ihMT high‐pass T 1D ‐filters. Conclusion Long‐T 1D components imaging by means of ihMT high‐pass T 1D ‐filters is proposed as an MRI biomarker for myelin content. Future studies should enable the investigation of the sensitivity of ihMT T 1D ‐filters for demyelinating processes.
Type of Medium:
Online Resource
ISSN:
0740-3194
,
1522-2594
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
1493786-4
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