Projects:longitudinaldwi

Description

Subject-specific analysis of image data often includes comparison of follow-up to baseline, or serial staging of progress of disease or for monitoring therapeutic intervention. Key methodological components are intra-subject registration of the set of scans, and analysis of geometric deformations and appearance changes. In DWI data, such analysis includes deformation of the set of DWI with associated correction of tensor orientation or local ODF adjustement. In addition, scalar invariants such as FA, MD, axial and radial diffusivities have to be compared in regions or along tracts at corresponding anatomical locations.

Constrained Data Decomposition and Regression for Longitudinal Fiber Tract Diffusion

We have developed a methodology based on constrained PCA (CPCA) for fitting age-related changes of white matter diffusion of fiber tracts. CPCA is applied to a functional data analysis (FDA) problem, where diffusion along parametrized fiber tracts, e.g. FA or MD, represent functions of arc-length. Age regression on tract functions reveals a nonlinear trajectory but also age-related changes varying locally along tracts.

Fiber tracts defined by tractography.

Longitudinal change of FA along mid-cc tract in aging (20-75 years).

Age regression of FA along mid-cc tract.

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Key Investigators

• Utah: Anuja Sharma, Sylvain Gouttard, Guido Gerig
• IOWA: Hans Johnson

Application to longitudinal DTI in Huntington Disease

to come soon