[BIC-announce] Q-Ball Imaging: Maxime Descoteaux Talk - Jan 18th

[Kaleem Siddiqi]

Dear Colleagues:

Maxime Descoteaux, who is visiting from INRIA Sophia-Antipolis,
will be giving a talk on his recent work:

Date: Wednesday, January 18th
Time: 2pm - 3pm
Place: McConnell 437

Title: Analytic ODF Estimation and Validation in Q-ball Imaging

Abstract:
Due the well-known limitations of diffusion tensor imaging (DTI), high 
angular resolu- 
tion diffusion imaging is currently of great interest to characterize 
voxels containing multiple fiber 
crossings. In particular, Q-ball imaging (QBI) is now a popular 
reconstruction method to obtain 
the orientation distribution function (ODF) of these multiple fiber 
distributions. The latter captures 
all important angular contrast by expressing the probability that a 
water molecule will diffuse into 
any given solid angle. However, QBI and other high order spin 
displacement estimation methods 
involve non-trivial numerical computations and lack a straightforward 
regularization process. In this 
talk, a simple linear and regularized analytic solution for the Q-ball 
reconstruction of 
the ODF is developed.  First, the signal is modeled with a physically 
meaningful high order spherical 
harmonic series by incorporating the Laplace-Beltrami operator in the 
solution. This leads to a 
mathematical simplification of the Funk-Radon transform using the 
Funk-Hecke theorem. 
In doing so, a fast and robust model-free ODF approximation is 
obtained. 
Comparative results are presented against Tuch's original QBI technique
on a biological phantom and on in-vivo human brain data.

Joint work with Rachid Deriche, Elaine Angelino and Shaun Fitzgibbons

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