Intrathecal gadolinium-enhanced magnetic resonance cisternography in cerebrospinal fluid rhinorrhea: road ahead?

Accurate localization of cerebrospinal fluid (CSF) fistula in a patient with CSF rhinorrhea is challenging and often involves multiple imaging studies with associated expense and patient discomfort. Intrathecal contrast-enhanced computed tomography (CT) and unenhanced magnetic resonance (MR) cisternography using constructive interference in steady state (CISS-3D) sequences are currently being used in attempt to localize the leakage site but with varying degrees of success. Our purpose is to evaluate the utility of intrathecal gadolinium-enhanced MR cisternography (GdMRC) in patients with CSF rhinorrhea. Ten consecutive patients of CSF rhinorrhea (five spontaneous, four post-traumatic, and one post-operative) were evaluated with GdMRC. Nine of the patients underwent intrathecal contrast CT and CISS-3D examinations in addition. Each of studies was reviewed independently by three neuroradiologists blinded to results of other modalities. Surgery was planned after consensus and surgical correlation obtained in nine cases. The fistulous site was clearly demonstrated by using GdMRC in eight patients, CISS-3D in six, and intrathecal CT in three patients. The site of leakage was confirmed surgically in all the patients. One patient was found to be false negative both by intrathecal CT and GdMRC, and in one patient no fistulous site was demonstrated by any of the modalities and surgery was not offered. No adverse reaction was seen in any of the patients. GdMRC is a novel method of confirmation and localization of CSF fistula with potential for routine clinical application. Diagnosis and localization of fistulous site is better demonstrated due to its high-contrast resolution, absence of bony artifacts, and direct multi-planar imaging.