1. NAMIC AHM, Jan 7-11, 2008 – Salt Lake City, Utah
Stochastic Tractography Group Study of Arcuate Fasciculus in Schizophrenia
Doug Markant,Tri Ngo, Marek Kubicki PNL, BWH
NAMIC AHM, Jan 7-11, 2008 – Salt Lake City, Utah

2. Methods 12 Controls, 7 Schizophrenia DWI Data: White matter mask
Final Study will have 18 Controls, 18 Schizophrenia
DWI Data:
3 T
Eddy Current Corrected
Rician Noise Filtered
White matter mask
Freesurfer Segmentation
ROI Generation
Superior Temporal Gyrus, Inferior Frontal Gyrus
Manual “Waypoint” ROI for tract selection

3. Methods Computational Resources:
Dual Core AMD Opteron(tm) Processor 880 x 8
63.05 GB ram
Average algorithm execution time per case:
40 mins

4. Methods: Inputs Stochastic Tractography Filter ROITract Filter
Max Length: 2000 mm
Step Size: 1 mm
Tract Samples/ROI voxel: 5000
Maximum bending: 90 degrees per segment
Stopping criteria: Max length, Leaving white matter mask
ROITract Filter
Tracts must pass encounter all 3 ROIs
Exclude tract inside ROI’s.

5. Previous Results

6. Results
Waypoint ROI

7. Results: Mean Subject FA, Connectivity>0.1
Blue: Control
Red: Schiz.

8. Results: Mean Weighted FA
Blue: Control
Red: Schiz.

9. Results: Mean Trace, Connectivity>0.1
Blue: Control
Red: Schiz.

10. Results: Mean Weighted Trace
Blue: Control
Red: Schiz.

11. Conclusions
Significant Increase in right mean trace in Schizophrenia Group.
Future Work:
Localized Tract Comparison using groupwise registration

12. Results: Overview FA
Trace
Mode
Subjects