Segmenting thalamic nuclei: what can we gain from HARdI?

The contrast provided by diffusion MRI has been exploited repeatedly for in vivo segmentations of thalamic nuclei. This paper systematically investigates the benefits of high-angular resolution (HARDI) data for this purpose. An empirical analysis of clustering stability reveals a clear advantage of acquiring HARDI data at b = 1000 s/mm2. However, based on stability arguments, as well as further visual and statistical evidence and theoretical insights about the impact of parameters, HARDI models such as the q-ball do not exhibit clear benefits over the standard diffusion tensor for thalamus segmentation at this b value.