Greater occipital nerve MR tractography: Feasibility and anatomical considerations

Background and purpose. - To assess the feasibility of greater occipital nerve (GUN) tractography using a fully automated tractography technique on the whole-neck volume, in comparison with anatomical knowledge. Methods. - Healthy 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: 1) value of 1000 s/mm(2), 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 GUN pathways on TWI maps. Results. - A total of 20 healthy subjects were included (12 males and eight females, mean age 53.8 years old). In comparison with anatomical atlas, GUN complete visualization (from C1-C2 origin to muscular emergence) was possible in 18 out of 20 healthy subjects. In two cases, CON was not visible in the cervical spine foramen. Conclusion. - Tractography through TWI is a feasible technique to accurately depict GUN. This technique may appear as a promising technique for therapeutic management of patients with occipital neuralgia. (C) 2017 Elsevier Masson SAS. All rights reserved.