Harmonic analysis of spherical sampling in diffusion MRI
Abstract
In the last decade diffusion MRI has become a powerful tool to non-invasively study white-matter integrity in the brain. Recently many research groups have focused their attention on multi-shell spherical acquisitions with the aim of effectively mapping the diffusion signal with a lower number of q-space samples, hence enabling a crucial reduction of acquisition time. One of the quantities commonly studied in this context is the so-called orientation distribution function (ODF). In this setting, the spherical harmonic (SH) transform has gained a great deal of popularity thanks to its ability to perform convolution operations efficiently and accurately, such as the Funk-Radon transform notably required for ODF computation from q-space data. However, if the q-space signal is described with an unsuitable angular resolution at any b-value probed, aliasing (or interpolation) artifacts are unavoidably created. So far this aspect has been tackled empirically and, to our knowledge, no study has addressed this problem in a quantitative approach. The aim of the present work is to study more theoretically the efficiency of multi-shell spherical sampling in diffusion MRI, in order to gain understanding in HYDI-like approaches, possibly paving the way to further optimization strategies.
- Publication:
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arXiv e-prints
- Pub Date:
- June 2011
- DOI:
- 10.48550/arXiv.1106.0269
- arXiv:
- arXiv:1106.0269
- Bibcode:
- 2011arXiv1106.0269D
- Keywords:
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- Quantitative Biology - Quantitative Methods;
- Physics - Medical Physics
- E-Print:
- 1 page, 2 figures, 19th Annual Meeting of International Society for Magnetic Resonance in Medicine