Eni Halilaj1, Cagatay Demiralp2, Stephen Correia3, David H. Laidlaw1
1Computer Science, Brown University, Providence, RI, USA; 2Computer Science, Brown University, Providence , RI, USA; 3Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Providence, RI, USA
We present six new quantitative tractography metrics for the assessment of white matter integrity in diffusion-tensor MRI. These metrics calculate a weighted total length of fiber tracts in brain tractography models. The weighting factors we use are well-established diffusion scalars, such as mean, axial, and radial diffusivity. The rationale for using these weighting factors is the fact that radial diffusivity is affected by demyelination whereas axial diffusivity is affected by axonal drop-out. Our findings suggest that these metrics can give hints on the nature of axonal damage, besides quantifying white matter deterioration.