A group-analysis tool for Freesurfer QDEC: A group-analysis tool for Freesurfer Nick Schmansky nicks@nmr.mgh.harvard.edu Martinos Center for Biomedical Imaging Massachusetts General Hospital

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

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?

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…

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…

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 email with links to results: Table data Snapshots of cortical surface Subcortical structure volumes, and volumetric maps

Demo of prototype QDEC Acknowledgements Overall concept - Bruce Fischl fischl@nmr.mgh.harvard.edu GLM fit development - Doug Greve greve@nmr.mgh.harvard.edu VTK/KWWidget development - Kevin Teich kteich@nmr.mgh.harvard.edu Subject processing - Jenni Pacheco jpacheco@nmr.mgh.harvard.edu and David Salat salat@nmr.mgh.harvard.edu