title: Structured sparsity for spatially coherent fibre orientation estimation in diffusion MRI.
abstract: We propose a novel formulation to solve the problem of intra-voxel reconstruction of the fibre orientation distribution function (FOD) in each voxel of the white matter of the brain from diffusion MRI data. The majority of the state-of-the-art methods in the field perform the reconstruction on a voxel-by-voxel level, promoting sparsity of the orientation distribution. Recent methods have proposed a global denoising of the diffusion data using spatial information prior to reconstruction, while others promote spatial regularisation through an additional empirical prior on the diffusion image at each q-space point. Our approach reconciles voxelwise sparsity and spatial regularisation and defines a spatially structured FOD sparsity prior, where the structure originates from the spatial coherence of the fibre orientation between neighbour voxels. The method is shown, through both simulated and real data, to enable accurate FOD reconstruction from a much lower number of q-space samples than the state of the art, typically 15 samples, even for quite adverse noise conditions.
authors.affiliation: Signal Processing Lab (LTS5), École Polytechnique Fédérale de Lausanne, Switzerland. Electronic address: anna.auria@epfl.ch.
authors.forename: A
authors.initials: A
authors.lastname: Auría
authors.affiliation: Signal Processing Lab (LTS5), École Polytechnique Fédérale de Lausanne, Switzerland; University Hospital Center (CHUV) and University of Lausanne (UNIL), Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Daducci
authors.affiliation: Signal Processing Lab (LTS5), École Polytechnique Fédérale de Lausanne, Switzerland; University Hospital Center (CHUV) and University of Lausanne (UNIL), Switzerland.
authors.forename: J-P
authors.initials: JP
authors.lastname: Thiran
authors.affiliation: Institute of Sensors, Signals & Systems, Heriot-Watt University, Edinburgh, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Wiaux
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D016208:Databases, Factual; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D009412:Nerve Fibers / Q000502:physiology*; D019047:Phantoms, Imaging; D066127:White Matter / Q000033:anatomy & histology / Q000166:cytology