MRI cisternography, and the localization of CSF fistulae

Accurate localization of CSF fistulae not only makes the planning of surgery easier, but it also increases the chances of successful dural repair and eliminates negative exploration. CSF fistulae localization has been a problem for many years, and several methods have been used to pin-point the site of CSF leakage with variable degree of success. Recently, contrast CT cisternography (CCTC) has replaced radio-isotope cisternography (RIC) in many centres. However, both methods are invasive, time consuming, contraindicated in patients with intracranial mass lesions and insensitive in detecting inactive CSF leaks. Furthermore, in both, ionizing radiation is used and both techniques may lead to allergic reactions or seizures. On the other hand, T2-weighted Magnetic Resonance Imaging (MRI) shows the CSF as a high signal without the need to inject contrast media intrathecally. Furthermore, MRI demonstrates the intracranial anatomy and pathology in detail in multiple planes within a relatively short time. MRI does not involve ionizing radiation and therefore is safely repeatable. MRI using T2-weighted sequences should be an ideal tool to locate precisely the site of CSF fistulae. This paper describes our experience with MRI cisternography in CSF fistulae localization. Eleven patients with inactive CSF fistulae were investigated. MRI cisternography localized the site of fistula in each case. All patients were explored surgically and the site of CSF fistula was confirmed and repaired intradurally with a pericranial graft and fibrin glue without recurrence or meningitis.