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Analysis and Results of Brockton VA study: Controls vs Schizophrenics Personality Disorder

Analysis and Results of Brockton VA study: Controls vs Schizophrenics Personality Disorder. Martin Styner, Ipek Oguz, UNC Jim Levitt, Martha Shenton, B&W, Brockton VA/Harvard`. TOC. NAMIC Data: SPD study Caudate shape analysis Steps of Shape Pipeline (simplified) Shape Analysis Results

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Analysis and Results of Brockton VA study: Controls vs Schizophrenics Personality Disorder

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  1. Analysis and Results of Brockton VA study:Controls vs Schizophrenics Personality Disorder Martin Styner, Ipek Oguz, UNC Jim Levitt, Martha Shenton, B&W, Brockton VA/Harvard`

  2. TOC • NAMIC Data: SPD study • Caudate shape analysis • Steps of Shape Pipeline (simplified) • Shape Analysis Results • Global & Local • Parcellation • Corpus Callosum segmentation and subdivision

  3. Data SPD study • Data through NAMIC • Manual segmentations of the caudate (with existing subdivision)

  4. Shape Analysis Workflow SPHARM- PDM Shape Preprocessing & Parameterization Caudate (Fusion) Segmentation QC Shape & Corresp. Feature Computation e.g. Subdivision or Mean Shape Difference Alignment & Scale QC of Features & Statistical Results Statistical Analysis Of Features

  5. Pre-processing • Sample case • Segmentation after pre-processing • Hole filling • 6 connect • Mean-curvature smoothing • 0.5mm^3 resolution

  6. SPHARM Shape • Spherical parameterization • Mirroring of right caudate • Alignment to first order ellipsoid • Alignment to template

  7. SPHARM Shape • Overlay of voxel segmentation (red) with SPHARM (blue) • Average Error ~ 0.11mm

  8. SPHARM correspondence

  9. SPHARM Mean Caudate Left Mean Right Mean • Cnt: Transparent blue, PSD: solid red, ICV scale • Difference between means

  10. Statistical Testing • Global Shape Difference • No Scale: Left: p = 0.13, Right: p = 0.016 • ICV Scale: Left: p = 0.46, Right: p = 0.062 • Local Significance (NoScale), Mean Diff, T2 lat L R L R med

  11. Caudate Subdivision • Skeleton based Subdivision (11 parts) • Fusion into 4 parts (ant/post head, body, tail)

  12. Caudate Subdivision • Subdivision Automatic QC images

  13. Caudate Subdivision ICV Scale Orig Scale same pattern all significant

  14. Caudate subdivision • Good agreement with local shape analysis L R L R lateral medial

  15. Caudate analysis • Prior work: • No diff. ant L and R, ICV + original • Diff. posterior region on R but not L • UNC subdivision • All subparts different in original scale • Ant L and R different in ICV scale • Diff posterior region on L and R • Explanation: • Variability cuts/intraventricular foramen • Region of cut shows difference in R in UNC subdivision • Small number of subjects

  16. Conclusion Caudate Study • Shape shows local and global differences on R, but only local on L • Subdivisions and local shape agree quite well • Both local shape analysis and subdivision suggest main effect in caudate head and some effect in parts of the tail

  17. Corpus Callosum • Methods & reliability • Results • How about other Brockton VA datasets? • General Witelson Scheme • Mostly manual • Can be automized

  18. CC segmentation • Automatic model based seg. • Start from average • Failure rate < 1% / 3% • In case of failure, manual correction of parameters

  19. Stable also with Anomalies

  20. CC subdivision • DTI fiber tracking based Corpus Callosum subdivision method • MICCAI 2005 Post-frontal Ant-frontal Parietal Occ+temp

  21. Probabilistic Subdivision • Not hard boundaries • 5 training datasets: Average model • Applicable on retrospective data Average Probabilistic Model

  22. Example Pediatric Growth • Regional Corpus Callosum growth in 4 pediatric cases age 2y to age 4y

  23. CC reliability • 100% reproducible segmentation, subdivision • 1 subject, 5 sites with 2 scans within 24h • T1, T2, PD: 1.5 mm & 3mm slice • Single rater (where manual) • Interp. to 1mm3, registration to ACPC atlas • 3 channel T1, T2, PD EMS for WM • T1 EMS for WM • Manual using T1 EMS • Manual model based (no parameter knowledge) • Pure manual (IRIS)

  24. EMS 3 Segmentation

  25. CC reliability • Model manual better than EMS1 manual • Model manual performed after EMS1: bias • Pure manual worst, only single case(better) • EMS3 shows best performance • Subdivision performs in the range of CC segmentation • Area measurements differ between methods

  26. CC Analysis in SPD data • No p-vals below 0.4 • No differences at all! • Is this negative finding expected? What have others found in this population? • How about the other datasets in NAMIC-VA: • Chronic schizophrenia (2 sets) • First episodes (2 sets) • We had findings before in other studies (autism, fragile X)

  27. ITK InsightSNAP • A level set semi- automatic segmentation tool • Visualization tool • Postprocessing tool • 5 year history • Here: use for caudate segmentation • Webpage with tools • Brief Demo of SNAP • Bools & 3D cuts

  28. Caudate Segmentation • Pediatric (2y & 4y) autism, fragile X, developmentally delayed and controls • Show document and figures • Protocol online available: • http://www.psychiatry.unc.edu/autismresearch/mri/roiprotocols.htm

  29. Other SNAP Projects • Segmentation of lateral ventricles using probability maps from tissue segmentation • ICC > 0.99, time ~ 10 min per case • Segmentation of mandible/maxilla for pre/post surgical evaluation from CB-CT

  30. The end (for now…)

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