RT info:eu-repo/semantics/article T1 Anisotropy measure from three diffusion-encoding gradient directions A1 Aja Fernández, Santiago A1 París Brandés, Guillem Lluis A1 Martín Martín, Carmen A1 Jones, Derek K. A1 Tristán Vega, Antonio K1 Anisotropy K1 Anisotropía K1 Brain K1 Cerebro AB We propose a method that can provide information about the anisotropy and orientation of diffusion in the brain from only 3 orthogonal gradient directions without imposing additional assumptions. The method is based on the Diffusion Anisotropy (DiA) that measures the distance from a diffusion signal to its isotropic equivalent. The original formulation based on a Spherical Harmonics basis allows to go down to only 3 orthogonal directions in order to estimate the measure. In addition, an alternative simplification and a color-coding representation are also proposed. Acquisitions from a publicly available database are used to test the viability of the proposal. The DiA succeeded in providing anisotropy information from the white matter using only 3 diffusion-encoding directions. The price to pay for such reduced acquisition is an increment in the variability of the data and a subestimation of the metric on those tracts not aligned with the acquired directions. Nevertheless, the calculation of anisotropy information from DMRI is feasible using fewer than 6 gradient directions by using DiA. The method is totally compatible with existing acquisition protocols, and it may provide complementary information about orientation in fast diffusion acquisitions. PB Elsevier SN 0730-725X YR 2022 FD 2022 LK https://uvadoc.uva.es/handle/10324/52106 UL https://uvadoc.uva.es/handle/10324/52106 LA eng NO Magnetic Resonance Imaging, 2022, vol. 88. p. 38-43 NO Producción Científica DS UVaDOC RD 02-abr-2025