Pacific Institute for the Mathematical Sciences - PIMS

This talk will present some of our recent work on spatial characterization of activation patterns in functional magnetic resonance imaging (fMRI) of the brain. Exploiting techniques for region of interest (ROI) characterization and statistical analysis provides a new perspective to brain activation studies. In particular, compensatory mechanisms in Parkinson's disease (PD) patients are being investigated. We use a new approach for characterizing the distribution of fMRI activation statistics of voxels inside an ROI by using three-dimensional (3D) shape descriptors based on 3D moment invariants. Results on fMRI data recorded from PD patients performing an internally or externally-cued finger sequences revealed that the patterns of activation regions were significantly different before and after medicine when patients used their dominant hands to perform the motor task. In contrast, no significant activation differences were detected using traditional intensity-based methods. These results suggest that modulations of activation distribution, as opposed to activation amplitudes, might function as the control mechanism for motor movements.

Rafeef Abugharbieh is currently an Assistant Professor at the Department of Electrical and Computer Engineering, University of British Columbia in Vancouver, Canada. She is the co-founder and co-director of BiSICL, the Biomedical Signal and Image Computing Laboratory, a new multidisciplinary research laboratory at UBC dedicated to computational research in biomedical applications. Dr. Abugharbieh received her Ph.D., Technical Licentiate, and M.Sc. (with distinction) degrees from the School of Electrical and Computer Engineering, Chalmers University of Technology in Goteborg, Sweden, in 2001, 1999, and 1996, respectively. She was a member of the Imaging and Image Analysis Group at the Department of Signals and Systems at Chalmers University from 1996-2001. In 1995 she obtained her B.Sc. degree in Electrical Engineering from the Faculty of Engineering and Technology at the University of Jordan in Amman, Jordan.