Utah Algorithms Progress and Future Work Tom Fletcher Ross Whitaker, PI

Overview Current progress and tools Future work Diffusion image filtering Registration of DWI White matter pathway analysis Future work Combining structural and diffusion data Particle-based shape analysis

Diffusion Image Filtering Diffusion-weighted images typically have very low SNR Noise in MRI is Rician, which is biased at low SNR We developed an edge-preserving filter to remove Rician noise in DWI Slicer module (Sylvain Gouttard) available in NA-MIC toolkit

DTI Filtering Slicer Module

DTI Filtering Result

DWI Registration Misregistration of DWI due to Eddy currents Head motion Implemented the method in Rohde, et al., MRM 2004 Registration software (Ran Tao) is available as a command line tool

Registration Result

White Matter Pathway Analysis Region-to-region analysis Volumetric representation of pathway Find minimal cost path in DTI data by solving a Hamilton-Jacobi PDE Pathway solver (Won-Ki Jeong) is available as a command line tool

White Matter Pathways

Regression of FA Raw Data Scatterplot Regression w/ std dev Genu of the Corpus Callosum (CC)

Combining Structural and Diffusion Imagery We would like to use cortical regions to seed white matter pathways Combine DTI analysis with grey matter / cortical thickness measures Major challenge is distortions in DWI due to field inhomegeneity Lack of open source tools to solve these problems

Particle-Based Shape Analysis Developed a particle-based method for automatic shape model and correspondence construction (Cates, et al., IPMI 2007) Handles complex geometry and topology Collaboration with UNC to extend to cortical surface correspondences (Oguz, et al., ISBI 2008 submission)

Conclusion Working towards an open source DTI processing pipeline Building tools for shape analysis Looking forward: combine structural with diffusion tensor imagery