We first use standard visualization techniques to investigate the
range of parameters in the data and and locate the starting region for
fiber tracing procedure. We then proceed with moving least squares (MLS) fiber
tracing method developed in Zhukov and Barr Zhukov02.
The basic steps of the MLS algorithm are:
Interpolate given 3D tensor data component-wise in the entire
volume and create a continuous tensor field.
Choose the seed region for the fibers (can be the entire volume).
Trace fibers individually using Moving Least Square (MLS) method for
dynamic regularization. Fibers will follow the regularized principal
direction (direction of the eigenvector with largest eigenvalue)
The tracing will stop when the fiber reaches the areas with below
the threshold value of chosen anisotropy parameter.
Render individual fibers as streamlines or stream-tubes.
Figure1:
Grayscalemapped value of diffusion tensor anisotropy
measure + for the ``short axes'' and ``long axes'' views
of the heart. The data is thresholded and all voxels with the signal
strength below the threshold value are zero out.