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fMRI within NAMIC. Sandy Wells, Polina Golland Discussion moderator: Andy Saykin. fMRI Update. Algorithms for time-series analysis Regularization/smoothing Segmentation/clustering Enabling methodologies Joint analysis with other modalitites Group analysis
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fMRI within NAMIC Sandy Wells, Polina Golland Discussion moderator: Andy Saykin
fMRI Update • Algorithms for time-series analysis • Regularization/smoothing • Segmentation/clustering • Enabling methodologies • Joint analysis with other modalitites • Group analysis • Core 1 / Core 3 projects to apply to clinical data • Core 1 / Core 2 projects to integrate into NAMIC-kit
fMRI Detection/Regularization • Smarter strategies for smoothing • MRF priors (MIT/BWH) • Wanmei Ou, Polina Golland, Sandy Wells • Surface-based vs. volumetric smoothing (MGH) • Anastasia Yendiki, Doug Greve, Bruce Fischl • Example: MIND fMRI reliability study • Sensorimotor paradigm • 10 subjects on 2 visits at each of 4 sites • We thank Randy Gollub for providing the MIND data
Surface Volume Surface vs. Volume Smoothing • Four subjects (fixed-effects, single visit), 15mm FWHM: • Demonstrated better detection power
Functional Hierarchy/Segmentation • Hierarchical clustering of time series data (MIT) • Polina Golland, Bryce Kim, Danial Lashkari, • Simultaneously estimate • Representative “signatures” • Which signature best describes each voxel • Example: diverse set of visual and mental tasks • localizer, rest, movie, etc.; ~1 hour of fMRI data • 7 subjects
Intrinsic Stimulus Dependent Visual Motor+Aud Motor+Aud STS+ Retinotopic High Visual ? ? High Visual ? ? STS Motor Auditory Hierarchy in Single Subject
Group Analysis of 2 systems Individual Maps Group Average
Enabling Methodologies Core 1 / Core 2 / Core 3
DTI-based Connectivity Analysis Path of interest analysis (MGH) Probabilistic tractography (MT/BWH/Harvard) Strength of connection between ROIs Tri Ngo, C-F Westin, Marek Kubicki, Polina Golland ROIs from fMRI Color Stroop in Schizophrenia 15 subjects in each group Implementation in NAMIC-kit in progress fMRI/DTI Connectivity
Anatomical Analysis • Cortical segmentation and flattening (MGH) • Freesurfer tools, now compatible with Slicer • Doug Greeve, Bruce Fischl, Steve Pieper • Conformal mapping of the cortex (Georgia Tech) • Yi Gao, John Melonakos, Allen Tannebaum • Filters in ITK
Aligned output Unaligned input Population Registration • Information-theoretic group-wise alignment (MIT/MGH/BWH) • Integration into NAMIC-kit in progress • In the fututre: non-rigid deformations using B-splines • Serdar Balci, Lilla Zollei, Mert Sabuncu, Sandy Wells, Polina Golland
Acquired Estimated EPI Registration/De-Warping • Combine segmentation and registration with Physics-based modeling of susceptibility (MIT/BWH/fMRIB) • Accurate registration of fMRI to anatomical MR • Retrospective correction of EPI distortions • Clare Poynton, Sandy Wells, Mark Jenkinson