The significance of computed tomographic findings in the diagnosis of fungus ball in the paranasal sinuses.

BACKGROUND: Sinus fungus ball (SFB), previously termed mycetoma of the paranasal sinus is a type of noninvasive fungal rhinosinusitis and the treatment of choice for this condition is functional endoscopic sinus surgery. Predicting the possibility of SFB by performing preoperative computed tomography (CT) is important to ensure appropriate treatment. Various studies have reported the CT findings of SFB. We aimed to investigate the relationship between CT features and SFB to increase the preoperative diagnostic accuracy of CT. METHODS: Based on a literature review, we selected six CT features of SFB including calcification, erosion of the inner wall of the sinus, sclerosis of sinus lateral wall, heterogeneous opacification of sinus, absence of an air-fluid level, and sinus mucosal thickening. From January 2004 to February 2010, 96 SFB patients and 72 unilateral chronic rhinosinusitis (CRS) patients were enrolled in this study. Preoperative CT images of all of the patients were interpreted by a radiologist and an otolaryngologist. RESULTS: All of the CT features except mucosal thickening showed statistically significant differences between SFB and CRS group patients. After adjusting for these CT features in a multiple logistic regression model, only the two features, viz., calcification and erosion of the inner wall of the sinus, were found to have a significant positive association with SFB. CONCLUSION: We found that five CT features, particularly calcification and erosion of the inner wall of the sinus, increase the diagnostic accuracy of CT for SFB, and this ensures that the patient receives appropriate treatment.