[Magnetic resonance imaging diagnosis of craniobasal cerebrospinal fluid fistulas by 3D-CISS sequence]

Recently, a Magnetic Resonance Imaging (MRI)-technique has been developed to diagnose the exact anatomical location of fistulas of the cerebrospinal fluid (CSF). This method is called 3D-constructive interference steady state-sequence (CISS) but it is not well known in clinical practice. Aim of the study was the evaluation of specificity and sensitivity of CISS-MRI. 12 patients with rhinoliquorrhea after head injury (n = 7) or skull base tumours (n = 5) were examined by CISS-MRI. The examinations were performed with a 1.5 T whole body MRI scanner in prone position and coronal plane sections. In cases of CSF leckage the sensitivity for detection of a CSF fistula was 100%. In comparison with intraoperative findings, specificity was 100%: in all cases, a dural lesion in anatomical correlation to MRI was detected. Further advantages of this method are its non-invasive character, no need for contrast application, no radiation exposure, and exact localisation of additional anatomical findings (brain herniation, brain contusions).