ODF reconstruction in q-ball imaging with solid angle consideration

• Published in: 2009 IEEE International Symposium on Biomedical Imaging: From Nano to Macro Vol. 2009; pp. 1398 - 1401
• Main Authors: Aganj, I., Lenglet, C., Sapiro, G.
• Format: Conference Proceeding Journal Article
• Language: English
• Published: United States IEEE 01.06.2009
• Subjects: Distributed computing; Distribution functions; high angular resolution diffusion imaging (HARDI); High-resolution imaging; Image reconstruction; Image resolution; Lattices; Magnetic resonance; Magnetic resonance imaging; magnetic resonance imaging (MRI); Orientation distribution function (ODF); q-ball imaging (QBI); solid angle; Solids; Spatial resolution; magnetic resonance imaging (MRI); Orientation distribution function (ODF); high angular resolution diffusion imaging (HARDI); solid angle; q-ball imaging (QBI)
• ISBN: 1424439310; 9781424439317
• ISSN: 1945-7928; 1945-8452
• DOI: 10.1109/ISBI.2009.5193327

Q-ball imaging (QBI) is a high angular resolution diffusion imaging (HARDI) technique which has been proven very successful in resolving multiple intravoxel fiber orientations in MR images. The standard computation of the orientation distribution function (ODF, the probability of diffusion in a given direction) from q-ball uses linear radial projection, neglecting the change in the volume element along the ray, thereby resulting in distributions different from the true ODFs. For instance, they are not normalized or as sharp as expected, and generally require post-processing, such as sharpening or spherical deconvolution. In this paper, we consider the mathematically correct definition of the ODF and derive a closed-form expression for it in QBI. The derived ODF is dimensionless and normalized, and can be efficiently computed from q-ball acquisition protocols. We describe our proposed method and demonstrate its significantly improved performance on artificial data and real HARDI volumes.