Parametric Dictionary Learning in Diffusion MRI

Sylvain Merlet (1) , Emmanuel Caruyer (1) , Aurobrata Ghosh (1) , Rachid Deriche (1)

1 ATHENA - Computational Imaging of the Central Nervous System

In this work, we propose an approach to exploit the ability of compressive sensing to recover diffusion MRI signal and its characteristics from a limited number of samples. Our approach is threefold. First, we learn and design a parametric dictionary from a set of training diffusion data. This provides a highly sparse representation of the diffusion signal. The use of a parametric method presents several advantages: we design a continuous representation of the signal, from which we can analytically recover some features such as the ODF; besides, the dictionary we train is acquisition-independant. Next, we use this sparse representation to reconstruct the signal of interest, using cross-validation to assess the optimal regularization parameter for each signal reconstruction. The use of cross-validation is critical in the L1 minimization problem, as the choice of the parameter is sensitive to the noise level, the number of samples, and the data sparsity. Third, we use a polynomial approach to accurately extract ODF maxima. In the last section, we motivate and describe the choice of experimental parameters for the HARDI contest.

Domaines: Imagerie médicale

Sylvain Merlet, Emmanuel Caruyer, Aurobrata Ghosh, Rachid Deriche. Parametric Dictionary Learning in Diffusion MRI. HARDI reconstruction workshop - ISBI - International Symposium on Biomedical Imaging, Alessandro Daducci and Jean-Philippe Thiran and Yves Wiaux, May 2012, Barcelona, Spain. ⟨hal-00697102⟩