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bioRxiv · 10.1101/2024.10.02.616308

Enhanced Structural Brain Connectivity Analyses Using High Diffusion-weighting Strengths

Yu, L.·Flinker, A.·Veraart, J.
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Abstract

Tractography is a unique modality for the in vivo measurement of structural connectivity, crucial for understanding brain networks and neurological conditions. With increasing b-value, the diffusion-weighting signal becomes primarily sensitive to the intra-axonal signal. However, it remains unclear how tractography is affected by this observation. Here, using open-source datasets, we showed that at high b-values, DWI reduces the uncertainty in estimating fiber orientations. Specifically, we found the ratio of biologically-meaningful longer-range connections increases, accompanied with downstream impact of redistribution of connectome and network metrics. However, when going beyond b=6000 s/mm2, the loss of SNR imposed a penalty. Lastly, we showed that the data reaches satisfactory reproducibility with b-value above 1200 s/mm2. Overall, the results suggest that using b-values above 2500 s/mm2 is essential for more accurate connectome reconstruction by reducing uncertainty in fiber orientation estimation, supporting the use of higher b-value protocols in standard diffusion MRI scans and pipelines.

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Yu, L., Flinker, A., Veraart, J.. 2024-10-03. Enhanced Structural Brain Connectivity Analyses Using High Diffusion-weighting Strengths. https://doi.org/10.1101/2024.10.02.616308

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