CT Brain Anatomy
Sinuses

Key points

  • The air cells and sinuses of the skull are highly variable in appearance

The skull contains air sinuses which are highly variable in appearance between different individuals.

Sinuses - CT brain - (bone windows)

Hover on/off image to show/hide findings

Tap on/off image to show/hide findings

Click image to align with top of page

Sinuses - CT brain - (bone windows)

  • The sphenoid sinus and ethmoid air cells are continuous with the nasal airways
  • The mastoid air cells are continuous with the middle ear

Frontal sinuses - CT brain - (bone windows)

Hover on/off image to show/hide findings

Tap on/off image to show/hide findings

Click image to align with top of page

Frontal sinuses - CT brain - (bone windows)

  • The frontal sinuses are highly variable in appearance
  • Many people have no frontal sinuses (bottom image)

Sphenoid sinuses - CT brain - (bone windows)

Hover on/off image to show/hide findings

Tap on/off image to show/hide findings

Click image to align with top of page

Sphenoid sinuses - CT brain - (bone windows)

  • The sphenoid sinus can be single or septated into multiple separate sinuses

Sphenoid sinus - clinical significance

  • In the context of trauma, a fluid level in the sphenoid sinus may be a sign of a basal skull fracture

Maxillary sinuses - CT brain - (bone windows)

Hover on/off image to show/hide findings

Tap on/off image to show/hide findings

Click image to align with top of page

Maxillary sinuses - CT brain - (bone windows)

  • Mucosal thickening is a very common incidental finding
  • This patient - who had coryzal symptoms - had an otherwise normal CT following head injury