Acute sinusitis is an acute inflammation of the nasal and paranasal sinus mucosa that last less than four weeks and can occur in any of the paranasal sinuses.
Fever, headache, postnasal discharge of thick sputum, nasal congestion and abnormal smell.
Usually following viral upper respiratory tract infection. Tooth caries, periapical abscess and oroantral fistulation lead to a spread of infection to the maxillary sinus. Cystic fibrosis and allergy are risk factors.
Other anatomical variants that may predispose to the inflammation include nasal septal deviation, spur and/or frontoethmoidal recess variants.
Opacification of the sinuses and air/fluid level best seen in the maxillary sinus. Cannot assess the extent of inflammation and its complications.
Better anatomical delineation and assessment of inflammation extension, causes and complications. Peripheral mucosal thickening, air/fluid level, air bubbles within the fluid and obstruction of the ostiomeatal complexes are recognized findings.
T1WI can differentiate between the mucosal thickening that is isointense to soft tissue and fluid that is hypointense. They are both hyperintense in T2WI. Inflamed mucosa enhances in post-contrast study while the fluid does not.
- erosion through bone
- dural venous sinus thrombosis
- intracranial extension
Treatment and prognosis
Conservative medical treatment until the inflammation subsides and treatment of the cause, e.g. dental caries. If becomes chronic sinusitis, functional endoscopic sinus surgery may be considered.