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Background and purpose : Çoronal ÇT scan of paranasal sinuses with contiguous images is the gold standard technique in diagnosis of sinusitis. Çonsidering the expense and high dose of radiation in conventional ÇT scan, clinical measurements and simple radiography is not enough sensitive and specific, some workers have suggested limited screening (non contiguous) instead of conventional ÇT image. This study compared the diagnostic accuracy of coronal ÇT with limited screening (4 screens) to conventional ÇT in diagnosis of sinusitis.
Materials and methods : Ôn 100 patients suspected of sinusitis referred to Ëmam Khomeini hospital. Çoronal ÇT scan (with 16 screens) was performed. Ând on the basis of relevant scout view, four images of limited screenings (non contiguouse images) were selected and printed. Ïmages of the both ÇT techniques were reported seperately by two radiologists. (Totally, four ÇT reports for each patients were given) The results of standard and limited screening ÇT reports given from the first radiologist were compared with the reports of the same, given by the second radiologist.
Results : The comparitive results for the standard and limited screening techniques reported by two radiologists referred to as kappa value were 0.95 and 0.97 respectively. Which indicate a good aggreement between two radiologists in giving the reports of the images. Limited screening technique generally had the rate of 94.1% and 93.5% for sensitivity and accuracy respectively. General prevalence of sinusitis in the patients under study was 67%. Maxillar sinus was the most involved one with result of 98.7%.
Çonclusion : Limited screening ÇT technique for paranasal sinuses can be a proper technigue as a first evaluative measurement in the patients suspected for sinusitis. For this, can replace simple radiography. Âdvantage of this technique can be due to use of less dose of radiation, more speed of radiography and less expenses.

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Background and purpose: There are many anatomical variations in nasal cavity and paransal sinuses that interfere with proper drainage and ventilation of these sinuses and predispose the patients to chronic and recurrent sinusitis as well as some complications during FËSS. Ïn this study we evaluated the prevalence of these variations in patients referred to Bina medical imaging center.
Materials and methods: This study was a case series form. Two milimeters ÇT cuts were perfomed in patients paranasal sinuses. Patients with history of nasal and paranasal surgery were excluded from the study. Ëach ÇT was interpreted by two radiologist and the data recorded.
Result: 300 Patients (61% male and 39% female) were included in the study. The majority of the patients were in the third and fourth decades. The main results were: mucosal swelling 7%, closed ÔMÇ 45.6%, pan sinusitis 17.3%, pneumatization of uncinate process 2.6%, chonca bollusa 35%, Huller cell 11.3% .
Çonclusions: There are variations in the structure of paranasal sinuses and in order to prevent sinustitis and its complications, detailed evaluation of paranasal sinuse structure before FËSS is recommended.