A Method for Clustering White Matter Fiber Tracts

L. O'Donnell, Kubicki M, M. E. Shenton, M. Dreusicke, W. E. L. Grimson, C.-F. Westin
AJNR
Volume 27, Number 5
2006

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Abstract

Background/Purpose: Despite its potential for visualizing white matter fiber tracts in vivo, diffusion tensor tractography has found only limited applications in clinical research, where specific anatomical connections between distant regions need to be evaluated. Here, we introduce a robust method for fiber clustering which guides the separation of anatomically distinct fiber tracts and enables further estimation of anatomical connectivity between distant brain regions.
Methods: Line-scan-diffusion-tensor images (LSDTI) were acquired on a 1.5 Tesla magnet. Regions of interest (ROIs) for several anatomically distinct fiber tracts were manually drawn, then white matter tractography was performed using the Runge-Kutta method to interpolate paths (fiber traces) following the major directions of diffusion, where traces were seeded only within the defined ROIs. Next, a fully automatic procedure was applied to fiber traces, grouping them according to a pairwise similarity function which takes into account the shapes of the fibers and their spatial locations.
Results: We demonstrated the ability of the clustering algorithm to separate several fiber tracts which are otherwise difficult to define (left and right fornix, uncinate fasciculus and inferior occipito-frontal fasciculus, and corpus callosum fibers).
Conclusion: This method successfully delineates fiber tracts that can be further analyzed for clinical research purposes. Hypotheses regarding specific fiber connections and their abnormalities in various neuropsychiatric disorders can now be tested.

Fiber tract clustering in the corpus callosum. Using a fractional anisotropy map (A), we drew a region of interest on the corpus callosum (B).Because fiber paths have similar shapes (C), clustering produces an inadequate result (D). If the user isolates a region of the corpus callosum containing fiber paths of different shapes, clustering is successful (E).

Reference

O'Donnell L, M K, Shenton ME, Dreusicke M, Grimson WEL, Westin CF. A method for clustering white matter fiber tracts. AJNR 2006;27(5).

Bibtex entry

@Article{odonnellAJNR06,
  author         = {L. O'Donnell and M, Kubicki and M. E. Shenton and M.       
                   Dreusicke and W. E. L. Grimson and C.-F. Westin},           
  title          = {A Method for Clustering White Matter Fiber Tracts},        
  journal        = {AJNR},                                                     
  year           = {2006},                                                     
  volume         = {27},                                                       
  number         = {5}
}

Grants

NIH U54-EB005149 (NAMIC), NIH P41-RR13218 (NAC), NIH K02-MH01110, NIH R01-MH50747

Research area

DTI