Global Shape Analysis Workflow

This workflow takes raw un-skull-stripped volumes in multiple groups/populations, or a Study-Design, and generates a scene file containing the models of the ROIs where the groups are different. It also reports the global 56 regional p-values.

Problem addressed by this workflow

Identifying the group differences between 2 populations in the global shapes of 56 cortical and sub-cortical ROIs. This workflow also generates DX models of all 56 ROIs which can be viewed as a scene in ShapeViewer.

Detailed Workflow Usage & Specifications

• Input: Any volumetric file format can be used for the raw unskull-stripped imput images (e.g., DICOM, DIrectories, Analyze, MNC, Nifti, etc.)
• Pre-processing
  • Image conversion to Analyze
  • Converting to 8-bit
  • Intensity Inhomogeneity correction
  • Skull-stripping
  • Affine Registration
• Auto Volume Parsing
  • Non-linear Registration to LPBA40 Atlas
  • 56 ROI Volume Parcellation
  • Mapping of ROI labels in native space
• 56 Shape Modeling and Refinement
• Between-Group Statistical Analyses
  • Compute various global shape measures for 56 ROIs (average mean curvature, surface area, volume, shape index, curvedness, fractal dimension)
  • Shape Measure Tabulation
  • Group comparisons per ROI
  • Compute p-values
• Generate and display scene file

URL: http://www.loni.ucla.edu/twiki/bin/view/CCB/PipelineWorkflows_GSA