A novel method for estimating connectivity-based parcellation of the human brain from diffusion MRI: Application to an aging cohort

TY - JOUR

T1 - A novel method for estimating connectivity-based parcellation of the human brain from diffusion MRI

T2 - Application to an aging cohort

AU - Coelho, Ana

AU - Magalhães, Ricardo

AU - Moreira, Pedro S.

AU - Amorim, Liliana

AU - Portugal-Nunes, Carlos

AU - Castanho, Teresa

AU - Santos, Nadine Correia

AU - Sousa, Nuno

AU - Fernandes, Henrique M.

N1 - Publisher Copyright: © 2022 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.

PY - 2022/6

Y1 - 2022/6

N2 - Connectivity-based parcellation (CBP) methods are used to define homogenous and biologically meaningful parcels or nodes—the foundations of brain network fingerprinting—by grouping voxels with similar patterns of brain connectivity. However, we still lack a gold standard method and the use of CBPs to study the aging brain remains scarce. Our study proposes a novel CBP method from diffusion MRI data and shows its potential to produce a more accurate characterization of the longitudinal alterations in brain network topology occurring in aging. For this, we constructed whole-brain connectivity maps from diffusion MRI data of two datasets: an aging cohort evaluated at two timepoints (mean interval time: 52.8 ± 7.24 months) and a normative adult cohort—MGH-HCP. State-of-the-art clustering techniques were used to identify the best performing technique. Furthermore, we developed a new metric (connectivity homogeneity fingerprint [CHF]) to evaluate the success of the final CBP in improving regional/global structural connectivity homogeneity. Our results show that our method successfully generates highly homogeneous parcels, as described by the significantly larger CHF score of the resulting parcellation, when compared to the original. Additionally, we demonstrated that the developed parcellation provides a robust anatomical framework to assess longitudinal changes in the aging brain. Our results reveal that aging is characterized by a reorganization of the brain's structural network involving the decrease of intra-hemispheric, increase of inter-hemispheric connectivity, and topological rearrangement. Overall, this study proposes a new methodology to perform accurate and robust evaluations of CBP of the human brain.

AB - Connectivity-based parcellation (CBP) methods are used to define homogenous and biologically meaningful parcels or nodes—the foundations of brain network fingerprinting—by grouping voxels with similar patterns of brain connectivity. However, we still lack a gold standard method and the use of CBPs to study the aging brain remains scarce. Our study proposes a novel CBP method from diffusion MRI data and shows its potential to produce a more accurate characterization of the longitudinal alterations in brain network topology occurring in aging. For this, we constructed whole-brain connectivity maps from diffusion MRI data of two datasets: an aging cohort evaluated at two timepoints (mean interval time: 52.8 ± 7.24 months) and a normative adult cohort—MGH-HCP. State-of-the-art clustering techniques were used to identify the best performing technique. Furthermore, we developed a new metric (connectivity homogeneity fingerprint [CHF]) to evaluate the success of the final CBP in improving regional/global structural connectivity homogeneity. Our results show that our method successfully generates highly homogeneous parcels, as described by the significantly larger CHF score of the resulting parcellation, when compared to the original. Additionally, we demonstrated that the developed parcellation provides a robust anatomical framework to assess longitudinal changes in the aging brain. Our results reveal that aging is characterized by a reorganization of the brain's structural network involving the decrease of intra-hemispheric, increase of inter-hemispheric connectivity, and topological rearrangement. Overall, this study proposes a new methodology to perform accurate and robust evaluations of CBP of the human brain.

KW - aging

KW - brain parcellation

KW - clustering

KW - diffusion MRI

KW - network neuroscience

KW - structural connectivity

U2 - 10.1002/hbm.25773

DO - 10.1002/hbm.25773

M3 - Journal article

C2 - 35274787

AN - SCOPUS:85126041465

SN - 1065-9471

VL - 43

SP - 2419

EP - 2443

JO - Human Brain Mapping

JF - Human Brain Mapping

IS - 8

ER -