Fig. 3: Clustering of tracts based on their associations with cardiovascular risk factors.

a Hierarchical clustering of tracts based on the Jaccard distance between patterns of association with CVRFs (significant vs. non-significant). Blue (cluster 1), orange (cluster 2), green (cluster 3) and red (cluster 4) indicate clusters of tracts with inter-tract distance <65% of the maximum distance. Grey indicates all other (i.e., not clustered) tracts. b Mean percentage of CVRFs significantly associated with each of the four clusters shown in a, for volume, ICVF, ISOVF and MTsat separately. Each dot represents a tract. AF arcuate fasciculus, CC corpus callosum (1 = rostrum, 2 = genu, 3 = rostral body, 4 = anterior midbody, 5 = posterior midbody, 6 = isthmus, 7 = splenium), CG cingulum bundle, CST cortico-spinal tract, FX fornix, ICVF intra-cellular volume fraction, IFO inferior fronto-occipital fasciculus, ILF inferior longitudinal fasciculus, ISOVF isotropic volume fraction, MLF middle longitudinal fasciculus, MTsat magnetization transfer saturation, OR optic radiation, SLF superior longitudinal fasciculus, UF uncinate fasciculus.