Localisation of a CSF fistula by metrizamide CT cisternography.

Localisation of a cerebrospinal fluid fistula in the nasal region is difficult. Lack of a suitable roentgen contrast medium for intrathecal use has earlier restricted the utility of cisternography. Metrizamide cisternography and CT have recently proved to be well tolerated and effective in revealing CSF fistulae. A case report of operatively treated CSF rhinorrhea recurring after three years is presented. With the help of CT metrizamide cisternography, the fistula could finally be localised in the sphenoidal sinus. The re-operation confirmed this finding. The technique of cisternography is described.