Sphenoid sinus fluid level in skull-base fractures.

The value of a sphenoid sinus fluid level in the diagnosis of a skull-base fracture was studied in two materials: one of 41 accident victims who died from brain injury an had their skull-base fracture verified at autopsy; and another of 36 patients with a sphenoid sinus fluid level visible on their emergency skull radiographs. The inclusion of sphenoid fluid in the diagnostic criteria for skull-base fracture improved the diagnostic accuracy from about 65% to about 80%. The false positive cases were caused by facial fractures. The false negative cases mainly occurred among severely ill patients, who had a small amount of sphenoid fluid and suboptimal radiographs.