5
Cranial Skull Base
Introduction
This chapter will cover basic anatomy of the cranial skull base along with common radiographic findings. The topics covered include developmental appearances and anatomical variants. Calcifications within the soft tissue of the brain are included in Chapter 6. Different portions of the cranial skull base will be seen on CBCT scans depending on the FOV used. Some of the radiographic findings covered in this chapter may not be visible on all scans and therefore should not be commented on by someone reviewing a scan.
Anatomy
This section will highlight anatomical landmarks of the cranial skull base and the bones they are a part of. Many of these landmarks are only identifiable when using a scan with a large field of view.
Axial
The axial figures (Figures 5.1–5.5) start from the superior aspect of the cranium moving inferiorly. The following anatomy is readily identifiable on axial views (Table 5.1).
Bone | Anatomical landmark | Figures visible on |
Frontal | Frontal sinus | 5.1 |
Ethmoid | Crista galli | 5.2 |
Sphenoid | Anterior clinoid process Sella turcica Posterior clinoid process Foramen lacerum Pterygoid process |
5.3 5.3 5.3 5.4 5.5 |
Temporal | Carotid canal Petrous ridge Mastoid process Styloid process |
5.4 5.4 5.5 5.5 |
Occipital | Clivus / occipital bone Foramen magnum |
5.5 5.5 |
Coronal
The coronal figures (Figures 5.6–5.11) start from the anterior aspect of the face moving posteriorly. The following anatomy is readily identifiable on coronal views (Table 5.2).
Bone | Anatomical landmark | Figures visible on |
Frontal | Frontal sinus | 5.6 |
Ethmoid | Cribriform plate Crista galli |
5.7 5.7 |
Sphenoid | Anterior clinoid process Posterior clinoid process Foramen lacerum Foramen rotundum Pterygoid process Vidian canal |
5.8 5.9 5.9 5.8 5.8 5.8 |
Temporal | Petrous ridge Mastoid process Sigmoid sinus depression |
5.11 5.10 5.10 |
Occipital | Jugular foramen | 5.11 |
Sagittal
The sagittal figures (Figures 5.12–5.15) start fro/>