The skull contains air sinuses which are highly variable in appearance between different individuals.
CT Brain Anatomy
Sinuses
Key points
- The air cells and sinuses of the skull are highly variable in appearance
Sinuses - CT brain - (bone windows)
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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)
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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)
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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)
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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