1. A group-analysis tool for Freesurfer
QDEC:
A group-analysis tool for Freesurfer
Nick Schmansky
Martinos Center for Biomedical Imaging
Massachusetts General Hospital

2. What problem does it solve?
There is an ever-growing collection of subjects processed by Freesurfer’s ‘recon-all’ stream: eg. Jenni Pacheco (MGH) has just completed Freesurfer processing of 400+ OASIS subjects
Researchers need a GUI tool to allow easy exploration of the morphometric data found in this and other subject groups

3. Explore data correlations:
Does subject age correlate with cortical thickness?
Does hippocampal volume correlate with cortical thickness in a particular region?
Is there a gender-diagnosis interaction in the thickness-age correlation?

4. What is QDEC?
QDEC is a new Freesurfer GUI tool (still under development) that runs on Linux and Mac OS X platforms
Query
Design
Estimate
Contrast
…demo in a minute…

5. What is QDEC? GUI Stats engine …demo in a minute…
Selection of subjects and possible discrete and continuous factors
Display of results as a map on the cortical surface
Stats engine
Based on the General Linear Model
User is shielded from the complexities of input (eg. the design and contrast matrices)
Command-line tool: mri_glmfit
…demo in a minute…

6. What are the long-term goals?
Client-server architecture supporting XNAT instantiations:
Web-interface allowing subject and factor selection
Submit GLM fit to server
Receive with links to results:
Table data
Snapshots of cortical surface
Subcortical structure volumes, and volumetric maps

7. Demo of prototype QDEC Acknowledgements
Overall concept - Bruce Fischl
GLM fit development - Doug Greve
VTK/KWWidget development - Kevin Teich
Subject processing - Jenni Pacheco and David Salat