[Endoscopically controlled ultrasound diagnosis of the paranasal sinuses].

261 patients with diseases of the paranasal sinuses were examined by ultrasound (A-Scan). Sinuscopy or surgery was performed on these patients. Samples for histologic examination were taken. The correlation between ultrasound, endoscopy and x-ray was 80-90%. In endoscopic histologic normal maxillary sinuses, however, x-ray examination led to wrong positive results five times as often as ultrasound examination did. X-ray examination was more accurate only in cases where the process was separated from the anterior wall of the maxillary sinus by a layer of air.