Analysis of the CT scan should be undertaken in a routine, standardized fashion to ensure that important details are not missed. To aid in this evaluation, a checklist has been developed which focuses on the most salient and potentially dangerous areas of the paranasal sinuses. Regular preoperative analysis using this system may prevent unforeseen technical difficulties and excess morbidity. Before obtaining a CT scan, the patient is placed on optimal medical therapy including antibiotics, and topical and occasionally systemic steroids. Coronal scans are then performed with 3 mm sections through the frontal and sphenoid sinuses and 2 mm sections through the ethmoid region.
Intravenous contrast is used.
The study is then analyzed focusing on specific critical anatomic landmarks. When additional information is required due to severe pathology or atypical anatomy, axial sections are added. Out of 300 CT examinations that where analyzed, a preoperative checklist was developed with eight items that must be evaluated preoperatively. Methods for the identification and analysis of this anatomy as well as the types of anatomic variation are discussed. We have found this evaluation to be extremely useful and efficacious in preventing morbidity in endoscopic sinus surgery.