The importance of computed tomography in preoperative diagnostics of polyposis nasi

Computed tomography (CT) is a very important diagnostic tool prior to endos copic nasal or paranasal sinus surgery. However, it is frequently notice du ring endonsal surgery of the paranasal sinuses, that the intraoperative res ults do not completely agree with the radiological ones. The objective of t he present study was to compare clinical and operative findings with those of CT investigations. We collected 200 cases treated during the past 2 year s and studied their CT reports. Paranasal sinuses were separated into six r egions, and the pathological changes due to sinusitis found by CT were clas sified into four groups. Altogether, we found a highly significant relation ship between CT and intraoperative findings (r = 0.44; P < 0.0001), but dif ferences were found in several regions. The highest correlation was found i n the anterior ethmoid bone area (r = 0.98), posterior ethmoid bone area (r = 0.53), maxillar sinus (r = 0.36) and sphenoid sinus (r = 0.35). There wa s only a low agreement in the case of frontal sinus and recessus frontalis. Possible factors such as time between CT and operation or inflammation are discussed. While CT is the image modality of choice in evaluating patients with chronic paranasal sinusitis, agreement to intraoperative findings is not perfect. This should be taken into consideration when planning function al endoscopic sinus surgery.