Hypoplasia of the sphenoid sinuses as a diagnostic tool in cystic fibrosis

Purpose: To measure and compare the size of the sphenoid sinuses in patient s with cystic fibrosis (CF) to patients with inflammatory sinonasal disease , and to correlate the size with number of CF mutations in each patient. Material and Methods. Ninety-six CF patients aged 5-47 years (median 19 yea rs) and 130 control patients aged 7-51 years (median 32 years) were examine d using coronal CT of the paranasal sinuses. In each patient, the CT image with the largest coronal area of the sphenoid sinuses was scanned into a Ma cintosh computer with image processing and analysis software. Largest coron al area and largest circumference of the right and left sphenoid sinuses we re automatically measured. Additionally, antero-posterior extension of the sphenoid sinuses was calculated from the lateral scanograms. CF patients we re grouped according to number of confirmed mutations (CF-0, CF-1, or CF-2) . Results: CF patients generally had small sphenoid sinuses. The largest diff erences for all parameters were observed between the CF-2 and the control g roups (p < 0.0001). No CF-2 patient had pneumatization beyond the prespheno id. The CF-0 and CF-1 groups consisted of two populations, one overlapping the CF-2 group and another overlapping the control group. Conclusion: Hypoplasia of the sphenoid sinuses is a characteristic finding in CF patients. When pneumatization of the basisphenoid is present, the exi sting CF diagnosis should be questioned.