HARDI Reconstruction contest:
Phantom for testing data.

HARDI Reconstruction contest
ISBI - San Francisco
April 7th, 2013

Emmanuel Caruyer, Dept of Radiology, University of Pennsylvania.

HARDI Challenge Phantom

Fiber geometries: The making of.

Outline

A. Fibers geometries

Towards connectivity-based evaluation of local reconstruction
Crossings, branchings, and co.

B. MR Signal Simulation

Evaluation of partial volume effect
Model for signal simulation

Perspectives

A. Fibers Geometry

Connectivity-based evaluation: Motivations

Motivations for a connectivity-based evaluation of
HARDI Reconstruction.

Challenging fibers configurations in he human brain

List of challenging fibers configurations in the brain.

Fiber geometries

Fiber geometries

B. MR Signal Simulation

Computation of the partial volume effect

Partial volume computation

Partial volume effect computation. Reproduced from [TG Close et al. Neuroimage (2009)]

Strategy adapted from the Numerical Fiber Generator
Subdivision in a grid of 9x9x9 subvoxels
In each subvoxel, only one compartment is accounted for.

For the Training and Testing data: about 100,000,000 (sub)voxels to compute!

Signal simulation

Diffusion weighted images

Noisy Diffusion-weighted images for the DSI scheme, SNR=10.

Based on CHARMED Moedl
Extra-axonal compartment is Gaussian anisotropic
Intra-axonal compartment follows Soderman cylinder model.

Thanks. Questions?