Inflammatory Conditions

CT Interpretation

Radiological findings:

Acute sinusitis:

Chronic Sinusitis:

Fungal Sinusitis:

Mucous Retention Cysts:

Mucocoeles/Pyocoeles:

CT Interpretation : It is ideal to classify the CT findings in a systematic way to plan a surgical road map. We use the following broad classification: Normal, Anatomical variants, Inflammatory disease and non inflammatory disease.

The inflammatory disease usually follows certain patterns. Either it may be a simple ostiomeatal unit disease or advanced disease. The advanced disease could be either frontoethmoid or sphenoethmoid pattern. Inflammatory disease may also be classified as:

1. Infundibular pattern

2. Ostiomeatal unit pattern

3. Sphenoethmoidal recess pattern

4.Sinonasalpolyposis

5. Sporadic or Unclassifiable pattern

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Radiological findings:

Acute sinusitis:

-Air fluid level

-Mucosal thickening

-Complete opacification of the sinus The finding, air-fluid level within the sinus may be mimicked by blood in the sinus due to recent trauma.

Fig. : Coronal Section: Acute frontal sinusitis; Fluid level in the frontal sinus.

Fig. : Coronal Section: Acute maxillary sinusitis;Mucosal thickening in the right maxillary sinus (Black arrow and fuild level in the (L) Maxillary sinus.

Fig. : Coronal Section: Acute ethmoidal sinusitis: Fluid level in the (R) Ethmoidal bulla, mucosal thickening in the (R) osteo-meatal unit and fluid in the (L) Concha bullosa. B: Bulla ethmoidalis and CB: Conchal bullosa.

Fig. : Coronal Section: Acute posterior ethmoidal sinusitis: Fluid level in the (L) Posterior Ethmoidal cell (Arrow).

Fig. : Coronal Section: Acute posterior Sphenoid sinusitis: Fluid level in the (R) Sphenoid sinus (Arrow).

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Chronic sinusitis:

- Ethmoid sinus is commonly involved

- Mucosal thickening

- Complete opacification

- Bone remodeling and thickening due to osteitis

- Polyposis

Fig. : Coronal Section: Chronic frontal sinusitis. Mucosal thickening in the (L) Frontal sinus (Arrow).

Fig. : Coronal Section: Chronic ethmoidal l sinusitis. Mucosal thickening in the (R) ethmoidal bulla and (L) Osteomeatal unit and middle meatus (Arrow).

Fig. : Coronal Section: Chronic maxillary and ethmoidal sinusitis. Mucosal thickening in the (R) Posterior ethmoids and and (L) Maxillary sinus and osteometal unit (Arrow).

Fig. : Coronal Section: Chronic ethmoidal l sinusitis. Mucosal thickening in the (L) Posterior ethmoidal sinus.

Fig. : Coronal Section: Chronic sphenoidal l sinusitis. Mucosal thickening in the (L) Sphenoid sinus (Arrow).

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Fungal sinusitis : Maxillary and ethmoid sinus are most commonly involved.

1. Allergic fungal sinusitis :

- Complete opacification of multiple paranasal sinuses, unilateral or bilateral.

- Sinus expansion and erosion of a wall of the involved sinus

- Scattered infra sinus high attenuation areas amid mucosal thickening on noncontrast scans.These areas are due to heavy metals like iron, manganese , calcium and inspissated secretions.

2. Sinus mycetoma: - Focal area of increased attenuation that is usually centered within a diseased sinus, usually maxillary.

3. Acute Invasive fungal sinusitis:

- Aggressive bone erosion with extension of disease into the adjacent soft tissues.

- Intra sinus high attenuation areas may not be present in acute invasive fungal sinusitis

- May be associated with orbital, intracranial and cheek soft tissue invasion

4. Chronic invasive fungal sinusitis: Nonspecific.

5. Chronic granulomatous fungal sinusitis: Nonspecific.

Fig. :Axial Section: Maxillary Sinus Mycetoma. Note high attenuation area in the maxillary sinus (Arrow).

Fig. : Coronal Section: Allergic fungal sinusitis involving (R) maxillary and ethmoidal sinuses. Note high attenuation area in the maxillary sinus (Arrow).

Fig. : Coronal Section: Allergic fungal sinusitis involving (R) ethmoidal sinuses. Note high attenuation area in theethmoidal sinuses (Arrow).

Fig. : Coronal Section: Allergic fungal sinusitis involving (R) maxillary and ethmoidal sinuses. Note high attenuation area in the maxillary sinus wuth expansion of the sinus with erosion of the anterior wall of the maxilla (Arrow).

Fig. : Coronal Section: Allergic fungal sinusitis involving (R) posterior ethmoidal sinuses with intra-cranial extension and (L) Maxillary and Ethmoidal sinuses. Note high attenuation area and erosion of the skull base on (R) side.

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Mucous retention cyst homogenous, well circumscribed hypodense to isodense mass, usually in maxillary sinus.

Mucocoele : Hypodense, nonenhancing mass that fills and expands the sinus cavity.

Pyocoele :Same as mucocoele with rim enhancement.

Fig. : Coronal Section:Mucous retention cyst in bilateral maxillary sinuses (Arrow).

Fig. : Axial Section: (R) Antra-choanal polyp. Notice antral (Star) and Choanal parts (Arrow).

Fig. :Coronal Section (L) Mucocoele of the Frontal sinus (Arrow) which has pushed the eye ball downwards and outwards (Star).

Fig. : Axial Section: Mucocoele of the (R) Posterior ethmoidal sinus (White Arr0w) and Sphenoidal sinus (Black Arrow).

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