Combined HRCT and MR Cisternography in the Evaluation of CSF Rhinorrhea

Abstract Background: Cerebrospinal fluid (CSF) rhinorrhea is a potentially devastating condition, that can lead to significant morbidity and mortality. So, accurate localization of the osseodural defect is important for effective surgical repair. The usual diagnostic technique is computed tomography (CT) cisternography. Because of its associated risks, alternative imaging approaches should be used. High-resolution CT (HRCT) is good in identifying the bony details, but CSF is poorly depicted. In contrast, magnetic resonance imaging (MRI) with 3D-CISS technique detect CSF track as a bright signal, but the detection of bony defect is poor. To overcome the defects of both techniques, we superimposed the images obtained from each modality with subsequent perfect surgical planning. Aim of Study: To assess the diagnostic value of combined HRCT and MR cisternography in the evaluation of CSF rhinorrhea. Results: Clinically all studied patients presented with CSF rhinorrhea. Of total 47 cases, the osseous defect was detected on HRCT in 44 cases with a sensitivity 94%. MR cisternography, delineated the flow of a CSF-like signal intensity that could be traced intracranially. Overlapping the CTs and MRIs correctly depicted the site of the CSF leak in 46/47 with a high sensitivity 97%, which was confirmed by the endoscopic sinus examination. The most common site of osseodural defect was at the ethmoid roof, followed by the frontal sinus and finally the sphenoid sinus. This is associated with meningocele in 33/46 (71.7%) and meningo-encephalocele in 10/46 (21.7%). Conclusions: Combined HRCT and unenhanced MR cisternography is a non-invasive diagnostic technique and should be the favorite approach to delimit the site of CSF leakage prior to surgical repair.