Figure 9. Fitting the ball and two-sticks model to simulated multi-direction diffusion data.

This is a demonstration of the ability of the tool to simultaneously fit more complex diffusion models and spectral information. However, a good initialization point (provided by FSL’s xfibers tool) is required. Simulated data with more diffusion directions (but correspondingly lower spectral SNR) provide a better estimate of fiber directions than lower numbers of directions, which is required for stable spectral fits when no information is shared. The xfibres initialized fit, achievable on real data, is compared with an artificial perfect initialization approach (which requires the ground truth) and the ground truth. Each metabolite simulates a different cellular compartmentalization and therefore has a different ground truth.