AUTHOR=Bosticardo Sara , Schiavi Simona , Schaedelin Sabine , Battocchio Matteo , Barakovic Muhamed , Lu Po-Jui , Weigel Matthias , Melie-Garcia Lester , Granziera Cristina , Daducci Alessandro
TITLE=Evaluation of tractography-based myelin-weighted connectivity across the lifespan
JOURNAL=Frontiers in Neuroscience
VOLUME=17
YEAR=2024
URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2023.1228952
DOI=10.3389/fnins.2023.1228952
ISSN=1662-453X
ABSTRACT=IntroductionRecent studies showed that the myelin of the brain changes in the life span, and demyelination contributes to the loss of brain plasticity during normal aging. Diffusion-weighted magnetic resonance imaging (dMRI) allows studying brain connectivity in vivo by mapping axons in white matter with tractography algorithms. However, dMRI does not provide insight into myelin; thus, combining tractography with myelin-sensitive maps is necessary to investigate myelin-weighted brain connectivity. Tractometry is designated for this purpose, but it suffers from some serious limitations. Our study assessed the effectiveness of the recently proposed Myelin Streamlines Decomposition (MySD) method in estimating myelin-weighted connectomes and its capacity to detect changes in myelin network architecture during the process of normal aging. This approach opens up new possibilities compared to traditional Tractometry.
MethodsIn a group of 85 healthy controls aged between 18 and 68 years, we estimated myelin-weighted connectomes using Tractometry and MySD, and compared their modulation with age by means of three well-known global network metrics.
ResultsFollowing the literature, our results show that myelin development continues until brain maturation (40 years old), after which degeneration begins. In particular, mean connectivity strength and efficiency show an increasing trend up to 40 years, after which the process reverses. Both Tractometry and MySD are sensitive to these changes, but MySD turned out to be more accurate.
ConclusionAfter regressing the known predictors, MySD results in lower residual error, indicating that MySD provides more accurate estimates of myelin-weighted connectivity than Tractometry.