BackgroundParanasal sinus CT has high sensitivity and specificity for sinusitis. However, this modality is costly and involves greater radiation exposure than plain radiographs.ObjectivesWe tried to compare 10-cut limited CT scan and standard CT scan in the diagnosis of sinusitis.Materials and MethodsWe conducted a cross sectional case series from August to December 2010 on 150 patients with non-randomized sampling method in academic hospitals related to medical school of Shahid Beheshti University of medical sciences. Using standard CT scan as the gold standard, the sensitivity and specificity of limited series were calculated for each sinus group.ResultsIn our study limited CT scan had a sensitivity of 92%, specificity of 94%, positive predictive value of 90% and negative predictive value of 95%.ConclusionsThe limited CT scan is useful for confirming the clinical diagnosis of sinusitis.