Atlas Building in DTI
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Research update. Atlas Building in DTI. Rémi Jean Casey Goodlett Guido Gerig. Project. Atlas building in DTI Atlas based on FA images Atlas based on tensor fields
Atlas Building in DTI
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Research update Atlas Building in DTI Rémi Jean Casey Goodlett Guido Gerig
Project • Atlas building in DTI • Atlas based on FA images • Atlas based on tensor fields Casey Goodlett, Brad Davis, Remi Jean, John Gilmore, Guido GerigImproved Correspondence for DTI Population Studies via Unbiased Atlas Building • Do studies using atlas
What’s an Atlas ? • Atlas: Average and variability of a population of images • Applications: Segmentation, population characterization Image 1 Deformations Atlas Image n
Previous work • Atlas based on FA images • 5 1 year old and 10 neonates • Possibility to transform fiber bundles: Atlas space <-> Image space
FA FA FA’’ warped Atlas of FA Transformations The pipeline Affine Transformation FA’’ FA’’ affined Fluid Deformation Averaging
Is it a good way to build an atlas ? • Diffusion Tensor Imaging • More information in tensorfields : scale, orientation • By working on the tensors, we expect more accurate results
Atlas (Affine, Fluid) Structural Operator Structural Average DTI Images (1:N) Scalar Images From Manifold Detector on FA H-fields (1:N) H-1-fields (1:N) New approach : tensors 1 step :: Registration
DTI Images Rotate Tensors based on JH-1 Tensor Averaging DTI Atlas H-fields (1:N) Riemannian Symmetric Space New approach : tensors 2 step :: Atlas formation
Full tracts On- and off-center regions Bundles obtained from 50 cases atlas by tractography
Results : DTI atlas building Old method: Trackings in 50 individual images New method: One tracking in the atlas and statistical analysis across population • Smaller variability across subjects. • FA seems lower due to smoothing of data, but separability of clusters is much better, and thus discrimination. • New method is very efficient (2months versus a few hours user time if atlas is built).
Results Neonate - 59 cases 1 year old - 25 cases 2 years old - 13 cases
Current and future work • 1 year old atlas with 90 cases • 60 Controls • 20 Schizophrenics • 10 MVM cases • Create an automatic pipeline to compute an atlas • Batchmake
Future work • Do statistics on the 90 cases atlas • Compare the different populations • Figure out how to compare the different atlases ? • And how to map new cases into the atlas ?
Thank you • Questions ?