OBJECTIVETo sum up the characteristics of computed tomography of allergic fungal sinusitis (AFS) and to compare the CT changes with the findings in the operation. The diagnostic role of CT scan was discussed.

METHODSThe CT scans of 21 patients diagnosed as AFS were analyzed. The patients ranged from 15 to 50 years old,there were 17 males and 4 females. The CT was scanned with both bony and soft tissue windows. The preoperative examinations included nasal endoscopy, skin prick test, total serum IgE and nasal secretion smear. The findings in the operation were compared with the preoperative CT scans. Histopathology and fungal smear were done postoperatively.

RESULTSEndoscopy showed that all patients had polyps with wasfy yellow or inspissated white secretion. Nine cases (11 sides) showed yellow-to-brown material similar to peanut butter in the nasal cavities. Nasal CT scan demonstrated unilateral lesion in 10 cases (10 sides) and bilateral lesions in 11 cases (22 sides), who were all pansinus diseases. CT scan demonstrated a sheet areas of high-attenuation like "ground glass" within sinuses coupled with soft tissue image around them. Bone erosion of anterior skull base was encountered in 3 cases (4 sides). One case showed the intracranial extension. Twenty cases had conceived nasal endoscopic sinus surgeries. One case underwent endoscopic sinus surgery combined with coronal approach. The yellow-to-brown material (allergic mucin) was detected in the cavities of 17 cases. Four cases had green-to-brown secretion like mud. After follow-up of 6 months to 7 years, 14 cases were cured, 7 cases improved. Among them, 3 cases had to get revision surgeries because of recurrence 2 years after surgery.

CONCLUSIONSThe characteristic of a sheet area of high-attenuation like " ground glass" within sinuses coupled with soft tissue image around them in computed tomography of nasal sinus, accompanied with invasive expansion or bone erosion, has a diagnostic significance for AFS.