Projects:CorpusFiberClustering

Objectives:

To measure differences in fractional anisotropy (FA), trace, mode, and volume of five subdivisions of the corpus callosum of schizophrenic patients vs. normal controls using an automatic clustering method and high resolution 3 Tesla data.

Key Investigators:

Harvard PNL: Marek Kubicki, Kate Smith, Martha Shenton MIT: Lauren O'Donnell, Carl-Fredrik Westin

Progress:

We are using a high resolution 3 Tesla scans, 1.7x1.7x1.7 mm, 51 diffusion directions, 8 baselines (data available to NAMIC investigators). So far we scanned 24 subjects, 12 chronic schizophrenics and 12 matched control subjects. Fiber tractography is performed on the whole brain, and then an automatic clustering method (O’Donnell et al., 2006), is applied. Midsagittal slice is then painted according to anatomical clusters, which results in 5, reliable clusters. Mean FA, mode, trace as well as volume of each clusters are obtained for each subject, and compared between groups.

Preliminary results show a reduced FA in the second cluster (CC2) of the corpus callosum in schizophrenics and a reduced volume in the third cluster (CC3) of schizophrenics, when compared with control subjects.

References:

O’Donnell LJ, Kubicki M, Shenton ME, Dreusicke MH, Grimson WE, Westin CF (2006): A method for clustering white matter fiber tracts. AJNR Am J Neuroradiol 27:1032-6.