Three-slice computerized tomography for the diagnosis and follow-up of rhinosinusitis.

Plain sinus radiography is the imaging technique most frequently used to investigate suspected rhinosinusitis, but it has low diagnostic sensitivity. Contiguous paranasal computerized tomography (CT) gives detailed information about the pathology, anatomy and anatomical variations of the paranasal sinuses, but this method also has limitations. The cost of using this technique for all cases of suspected rhinosinusitis is prohibitive, and complete CT scans involve considerable radiation exposure. The aim of this study was to devise a CT protocol for diagnosing and following rhinosinusitis that is more economical and involves much less radiation exposure than contiguous CT. In this retrospective study, three physicians independently reviewed the contiguous coronal paranasal CT studies of 136 patients. The study population comprised the adult patients who were investigated for suspected chronic rhinosinusitis. All scans had been obtained at the second visit, after the patient had completed a 3-week course of medical treatment. For each case, the same three slices were selected to form the "three-slice CT" exam, and the same physicians independently evaluated this set. Using the results from the contiguous set as the gold standard, we calculated the sensitivity and specificity of three-slice CT for identifying rhinosinusitis. The sensitivity and specificity of three-slice CT for identifying inflammatory sinus disease were 95.1 and 92.6%, respectively. Three-slice CT is a valuable method for diagnosing and following rhinosinusitis cases, and would be cheaper and involve less radiation exposure than contiguous coronal CT. However, despite the high cost and greater radiation exposure, contiguous CT remains the gold standard for evaluating detailed sinus anatomy and disease progression.