DBP2:UNC:Regional Cortical Thickness Pipeline

Back to UNC Cortical Thickness Roadmap

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Objective

We would like to create an end-to-end application within Slicer3 allowing individual and group analysis of regional cortical thickness.

This page describes the related pipeline with its basic components, as well as its validation.

Pipeline overview

A Slicer3 high-level module for individual cortical thickness analysis has been developed: ARCTIC (Automatic Regional Cortical ThICkness)

Input: RAW images (T1-weighted, T2-weighted, PD-weighted images)

• 1. Tissue segmentation
  • Probabilistic atlas-based automatic tissue segmentation via an Expectation-Maximization scheme
  • Tool: itkEMS (UNC Slicer3 external module)
• 2. Regional atlas deformable registration
  • 2.1 Skull stripping using previously computed tissue segmentation label image
    • Tool: SegPostProcess (UNC Slicer3 external module)
  • 2.2 T1-weighted atlas deformable registration
    • B-spline pipeline registration
    • Tool: RegisterImages (Slicer3 module)
  • 2.3. Applying transformation to the parcellation map
    • Tool: ResampleVolume2 (Slicer3 module)
• 3. Cortical thickness measurement
  • Sparse asymmetric local cortical thickness
  • Tool: CortThick (UNC Slicer3 external module)
• 4. Statistics
  • Volume information (WM, GM, CSF, lobes) stored in spreadsheet
  • Tools: ImageMath, ImageStat (UNC Slicer3 external modules)
• 5. Mesh creation
  • White matter and grey matter meshes creation
  • Tool: ModelMaker (Slicer3 module)
• 6. MRML scene creation for quality control
  • MRML scene creation allowing quality control for each step of the pipeline
  • Output images and surfaces are automatically displayed

All the tools used in the current pipeline are Slicer3 modules, some of them being UNC external modules. The user can thus compute an individual regional cortical thickness analysis by running the 'ARCTIC' module, either within Slicer3 or as a command line.

ARCTIC Download

CVS access, Executables and tutorial dataset

Available on NITRC : http://www.nitrc.org/projects/arctic/

Complementary Downloads

Brain atlases

Three brain atlases are available on MIDAS:

• Pediatric atlas: http://www.insight-journal.org/midas/item/view/2277
• Adult atlas: http://www.insight-journal.org/midas/item/view/2328
• Elderly atlas: http://www.insight-journal.org/midas/item/view/2330

Tutorials

• ARCTIC tutorial : end-to-end Slicer3 module to perform automatic regional cortical thickness analysis‏ [ppt]‏ [pdf]

• UNC Modules tutorial : UNC Slicer3 modules to perform regional cortical thickness analysis step by step [ppt]‏ [pdf]‏

T1-weighted skull-stripped image

Parcellation image

Cortical thickness on WM surface

Cortical thickness information

Pipeline validation

Analysis on a small pediatric dataset

Tests have been computed on a small pediatric dataset which includes 2 year-old and 4 year-old cases.

• 16 autistic cases
• 1 developmental delay
• 3 normal control

Comparison to state of the art

We would like to compare our pipeline with FreeSurfer. We have thus started a regional statistical analysis using Pearson's correlation coefficient on an adult dataset (FreeSurfer's publicly available dataset) including 40 cases.

Planning

Done

• Workflow for individual analysis (Slicer3 external module using BatchMake)
• 2 Tutorials with application example on a small dataset : "How to use the UNC modules to compute the regional cortical thickness" and "How to use ARCTIC"
• Pediatric and adult brain atlases available to the community via MIDAS
• ARCTIC available to the community via NITRC: executables (UNC external modules for Slicer3) and Tutorial dataset
• New version including quality control through MRML scene, and WM, GM models generation
• ARCTIC source code (SVN, CVS) available to the community
• ARCTIC executable can be downloaded directly within Slicer3 using the extension wizard

In progress

• Comparison to FreeSurfer (40 cases dataset): pearson correlation analysis
• Mac and windows executables available on to the community through NITRC
• Input images orientation automatically managed by ARCTIC