Computed Tomography Cisternography in the Evaluation of Traumatic CSF Rhinorrhea.

The purpose of this study is to evaluate the use of computed tomographic cisternography (CTC) with nonionic water soluble contrast medium in the detection of the site of leakage in patients with traumatic cerebrospinal fluid (CSF) rhinorrhea. From July 1987 to December 1991, 33 cases of clinically suspected post-traumatic CSF fistula were reviewed. There were 26 males and 7 females, presenting clinically as CSF rhinorrhea or meningitis. A total of 22 CTC studies were performed in 20 cases in a prone position. Results were evaluated and considered positive according to one of the following three criteria: A) demonstration of contrast medium throught the bony defect , B) a bony defect with extracranial contrast medium adjacent to the bony defect, and C) visualization of contrast medium within one paranasal sinus or nasal cavity. Fourteen scans were positive (64%). They were criterion A in three scans, criterion B in six, criterion C in one, criteria A& B in two and criteria B&C in two. Criterion B was the most common. In eight scans, CTC examination was normal. The most common sites of CSF leak in decreasing frequency were the ethmoid sinus, the frontal sinus, the cribriform plate and the sphenoid sinus. Although the use of MRI has been reported in recent years, CT cisternography is still a valuable technique in the evaluation of patients with traumatic CSF rhinorrhea, not only delineating the contrast leakage, but also detecting the bony defect or the site of the fistula.