MAGNETIC-RESONANCE CISTERNOGRAPHY AND THIN CORONAL COMPUTERIZED-TOMOGRAPHY IN THE EVALUATION OF CEREBROSPINAL-FLUID RHINORRHEA

In recent years cerebrospinal fluid (CSF) rhinorrhea has been managed successfully with transnasal endoscopic techniques. The most important and often most difficult step is the precise localization of the fist ula. Computerized tomographic and radionuclide cisternography are two commonly used techniques for preoperative identification of the CSF fi stula when it cannot be seen clearly with nasal endoscopy. Each of the se requires a lumbar puncture, and the intrathecal placement of contra st material has been associated with transient neurotoxicities. Magnet ic resonance cisternography (MRC) is a noncontrast study that does not require a lumbar puncture and has been used recently in the diagnosis of spontaneous and traumatic CSF leaks. Magnetic resonance cisternogr aphy utilizes a fast spin-echo sequence with fat suppression and video image reversal that highlights CSF. This allows precise localization of the fistula in both coronal and sagittal planes. Thin section coron al computed tomography (TCCT) is another noninvasive technique that ca n be helpful in localizing CSF leaks. The technique of MRC and TCCT an d the results of 16 CSF leaks in 15 patients are reported. There was g ood correlation between MRC, TCCT, and intraoperative findings. Magnet ic resonance cisternography and thin coronal computerized tomography a ppear to be accurate and complementary, noninvasive radiographic studi es that should be considered in the evaluation CSF rhinorrhea.