Anatomy Monday: Cervical Vertebra 1 (C1 or Atlas)

Since I showed a case of a posterior cleft of C1 last week I thought I’d follow up with some key anatomy of C1 as seen on cone beam computed tomography (CBCT) images. These are all axial views that have been rotated as such to show the entire ring on one view.

Here is a drawing (from here) along with CBCT rotated axial views (one with annotations and one without) to show the key anatomy when viewing the arch.

Here’s another drawing (from here) showing the fusion points of C1; hence the possibilities of non-fusion at those locations.

Please let me know if you have any questions. Thanks and enjoy!