BACKGROUND AND PURPOSE:We evaluated the use of MR cisternography after intrathecal administration of gadopentetate dimeglumine to detect the presence and localization of CSF leaks in 19 patients diagnosed with spontaneous intracranial hypotension syndrome according to the criteria of International Headache Society.

BACKROUND AND PURPOSE:Radiologic identification of the location of the CSF leakage is important for proper surgical planning and increases the chance of dural repair. This article describes our experience in analyzing clinically suspected cranial CSF fistulas by using MR imaging combined with the intrathecal administration of a gadolinium-based contrast agent. MATERIALS AND METHODS:A total of 85 consecutive patients with suspected CSF fistulas who presented with persistent or intermittent rhinorrhea or otorrhea lasting for more than 1 month between 2003 and 2007 were included in this study. RESULTS:We observed objective CSF leakage in 64 of 85 patients (75%). The CSF leak was located in the ethmoidal region in 37 patients (58%), in the superior wall of the sphenoid sinus in 8 patients (13%), in the posterior wall of the frontal sinus in 10 patients (15%), in the superior wall of the mastoid air cells in 6 patients (9%), and from the skull base into the infratemporal fossa in 1 patient (2%). Two patients (3%) showed leakage into Ͼ1 paranasal sinus.CONCLUSIONS: MR cisternography after the intrathecal administration of gadopentate dimeglumine represents an effective and minimally invasive method for evaluating suspected CSF fistulas along the skull base. It provides multiplanar capabilities without risk of radiation exposure and is an excellent approach to depict the anatomy of CSF spaces and CSF fistulas. CSF leakage implies abnormal communication between the subarachnoid space and the nasal or middle ear cavity. It is generally classified as traumatic, nontraumatic (ie, spontaneous), or postsurgical in origin, 1 and most cases are traumatic. Approximately 70% of traumatic CSF fistulas close spontaneously within 1 week after injury without surgical intervention.2-4 However, even in cases of mild CSF rhinorrhea or early spontaneous closure, patients remain at risk of recurrent CSF leakage, pneumocephalus, and infectious meningitis. Precise identification of the location of the CSF fistula allows proper surgical planning, increases the chance of dural repair, and can prevent complications. 5,6 Numerous techniques, including plain skull radiography, intraoperative injection of fluorescein dye, positive contrast (iophendylate) studies, and radionuclide cisternography, are all helpful in limited ways.7-12 MR imaging with T2-weighted sequences has been used to localize CSF fistulas. The demonstration of high-signal-intensity fluid extending from the subarachnoid space directly into the adjacent paranasal sinuses or herniation of the brain into a sinus through a bone defect has been the principal diagnostic criterion.2,13-18 However, some or all of these findings can occasionally be observed in the absence of fistula formation on MR images obtained for reasons other than CSF leakage. The most common method for evaluating a patient with suspected CSF rhinorrhea is a combination of thin-section CT and subsequent CT cisternography (CTC). Although high-resolution CT (HRCT) is sufficient to show bony defects in the skull base...