The hypodensity reflects cysts, mucosal disease, and granulation tissue. Mucocele 3 This companion case nicely demonstrates bilateral mucoceles. The findings are:.
It presents as a unilateral nasal polyp arising from the lateral nasal wall, usually in the region of the middle meatus and middle turbinate. Eur Radiol. This patient had acute sinusitis which was complicated by orbital cellulitis and dacrocystitis with abscesses. This patient has an encephalocele.
On the left side there is also edema of the surrounding tissue. Fibrous dysplasia is a very vascular lesion and can enhance avidly. This is also called Pott's puffy tumor after Sir Pott, an English surgeon who first described this entity. The coronal CT nicely demonstrates remodelling of the bone and expansion arrowheads.
The differential diagnosis is a meningioma.
Pierse JE, Stern A. Knowledge of the etiologies discussed here and a systematic approach when reviewing images can be helpful in both narrowing the differential and formulating a correct diagnosis. The sphenochoanal polyp typically lies between the nasal septum and the middle turbinate Figure 10 ; this space is clear with antrochoanal polyps. CT and MR have a complimentary role in this case, but finally a biopsy is called for to differentiate between these two diagnoses, because of different treatment.
Three months into therapy the skull-base mass has resolved. Fibrous dysplasia 2 On the left another example of fibrous dysplasia. Osteoma This is a patient who had been having brain MRI for the past 1,5 yrs for frontal headaches.
The mycetoma represents a densely packed collection of fungal hyphae with no allergic mucin. On this contrast-enhanced MRI we see a non-enhancing expansile lesion in the right maxillary sinus.
The signal characteristics on MRI and the attentuation on CT are a result of the high protein content of fungus. CT is usually diagnostic, so when you see a bizarre lesion at the skull-base, think of a fibro-osseous lesion and get an unenhanced CT.
Radiology quiz case 1.