Figure 1
From: Diattenuation Imaging reveals different brain tissue properties
Diattenuation Imaging: combined measurement of 3D-PLI (left) and diattenuation (right), shown exemplary for a sagittal rat brain section of 60 μm thickness, measured with the LAP with an effective object-space resolution of 14 μm/px (see Methods). (a,d) Measurement set-up consisting of a pair of crossed linear polarisers and a quarter-wave retarder rotated by angles ρ = {0, 10, …, 170}°. (b) 3D-PLI and diattenuation signals (transmitted light intensities I(ρ)). The phase and amplitude of the 3D-PLI signal (φP, |sin δP|) are directly related to the in-plane and out-of-plane orientation angles (φ, α) of the nerve fibre, respectively. The phase and amplitude of the diattenuation signal (φD, \(|{\mathscr{D}}|\)) are derived from the maximum and minimum transmitted light intensities (Imax, Imin) using equation (1). (c) The coloured diattenuation image (middle image) is computed from the strength of the diattenuation signal \(|{\mathscr{D}}|\), considering the phases {φP, φD} of the 3D-PLI and diattenuation signals: all \(|{\mathscr{D}}|\) values belonging to regions with (φD − φP) ∈ [−20°, 20°] are colourised in green (D+), regions with (φD − φP) ∈ [−70°, 110°] are colourised in magenta (D−), see peaks in histogram. The average transmitted light intensity \({I}_{{\rm{T}}}=\overline{I(\rho )}\) of the brain section is shown in Supplementary Fig. S3a.
