Magnetic resonance cisternogram with intrathecal gadolinium with delayed imaging for difficult to diagnose cerebrospinal fluid leaks of anterior skull base.

ABSTRACT

BACKGROUND: Workup of cerebrospinal fluid (CSF) leaks can be challenging. Patients with intermittent or infrequent clear rhinorrhea that cannot be collected, those with questionable or multiple skull-base (SB) defects on imaging, and those with previous SB surgery can present diagnostic dilemmas. In this patient population, radiologic studies that allow repeat imaging over hours to days can increase the diagnostic yield. We report our experience with magnetic resonance cisternogram with intrathecal gadolinium (MRCgGd) in this patient population. METHODS: This study was a retrospective review of patients who underwent MRCgGd for workup of suspected CSF leaks at a tertiary care academic center. RESULTS: Over the past 3 years, 11 patients (10 females; mean age 50 years) underwent MRCgGd. Seven patients had suspected spontaneous CSF leaks from idiopathic intracranial hypertension and 2 had postsurgical defects. All patients had previous imaging that was indeterminate in localizing the site of the leak. Only 3 patients had positive beta-2 transferrin studies, all with multiple potential leak sites. MRCgGd confirmed the absence of leaks at 4 previously repaired SB defects, identified spinal canal leaks but no SB leaks in 2 patients (1 of whom had a nonleaking SB defect), and identified 5 patients with one or more SB leaks. Repeat imaging, from 30 minutes to 20 hours, was beneficial in identifying 4 leaks not confirmed in the immediate imaging, and ruling out leaks in 5 cases, therefore guiding further treatment. No complications occurred. CONCLUSION: MRCgGd is a useful diagnostic test in the workup of patients with difficult CSF leaks, with delayed imaging providing valuable diagnostic information.