Greater occipital nerve MR tractography: Feasibility and anatomical considerations

Abstract

Background and purposeTo assess the feasibility of greater occipital nerve (GON) tractography using a fully automated tractography technique on the whole-neck volume, in comparison with anatomical knowledge. MethodsHealthy subjects were consecutively included in this study if they had no history or symptoms of headache or brain disorder. A 3T MRI scanner with a 32 channel head coil was used. The following parameters for Diffusion Weighed (DWI) were used: b value of 1000 s/mm2, 32 directions, acquired voxel size: 2 mm isotropic. High-Order tractography with the Constrained Spherical Deconvolution (CSD) model was generated. Track-Weighted Imaging (TWI) maps were generated with MRTrix. Two radiologists performed blind evaluations of the GON pathways on TWI maps. ResultsA total of 20 healthy subjects were included (12 males and eight females, mean age 53.8 years old). In comparison with anatomical atlas, GON complete visualization (from C1–C2 origin to muscular emergence) was possible in 18 out of 20 healthy subjects. In two cases, GON was not visible in the cervical spine foramen. ConclusionTractography through TWI is a feasible technique to accurately depict GON. This technique may appear as a promising technique for therapeutic management of patients with occipital neuralgia.