Correlational Tractography

Before practicum on Friday, please complete following:

Review Paper

Correlational tractography tutorial


During practicum on Friday:

Correlation tractography

  Conventional fiber tracking Differential fiber traacking Correlational Tractography
seed point start at any white matter location start at any white matter location start at any white matter location
propagation propagate along fiber orientation propagate along fiber orientation propagate along fiber orientation
termination criteria anisotropy threshold, angular threshold anisotropy threshold, angular threshold, threshold for the anisotropy decrease anisotropy threshold, angular threshold, threshold for the t-statistics

Connectometry

Connectometry: a statistical method using permutation test and bootstrap resampling to test the significance of correlational tractography.

Steps

Types

study type correlation type examples of null hypothesis
cross-sectional correlation with a categorical variable the tractography with decreased metrics in group 1 is the same as those after group permutation.
cross-sectional correlation with a continuous variable the tractography with decreased metrics correlated with age is the same as those after age permutation.
longitudinal increased of decreased the tractography with decreased metrics is the same as those after random-permuting the sign of change.
longitudinal associated with a categorical variable the tractography with decreased metrics in group 1 is the same as those after group permutation.
longitudinal associated with a continuous variable the tractography with decreased metrics correlated with age is the same as those after age permutation.

Hands-on: cross-sectional analysis

data: SCA2 cross sectional database and demographics

Hands-on: longitudinal analysis

data: SCA2 longitudinal database