Section: New Results

Iconic-Geometric Nonlinear Registration of a Basal Ganglia Atlas for Deep Brain Stimulation Planning

Participants : Ana Fouquier, Stanley Durrleman, Jérôme Yelnik, Sara Fernandez-Vidal, Eric Bardinet.

We evaluated a nonlinear registration method for warping a 3D histological atlas of the basal ganglia into patient data for deep brain stimulation (DBS) planning. The power of the method is the possibility to combine iconic registration with geometric constraints under a unified diffeomorphic framework. This combination aims to ensure robust and accurate atlas-to-patient warping and anatomy-preserving deformations of stimulation target nuclei. A comparison of the method with a state-of-the-art diffeomorphic registration algorithm reveals how each approach deforms low-contrasted image regions where DBS target nuclei often lie. The technique is applied to T1-weighted magnetic resonance images from a cohort of Parkinsonian subjects, including subjects with standard-size and large ventricles. Results illustrate the effects of iconic or geometric registration alone, as well as how both constraints can be integrated in order to contribute for registration precision enhancement. See Fig. 2 .

Figure 2. Superimposition of deformed meshes of the histological atlas with a patient pre-operative MRI. Meshes in bright colors result from a block-matching algorithm based on image intensity. Meshes in dark colors result from our iconic-geometric approach with non-linear deformation. We observe a better alignment of the structures, as well as a realistic deformation of the sub-thalamic nucleus (in yellow/orange), which is not visible in the image and therefore has not been taken into account for estimating the optimal deformation. This nucleus is the stimulation target for patients with Parkinson's disease.

More details in [25] .