The aim of this prospective study was to evaluate the value of unenhanced 
(three-dimensional constructive interference in steady state (3D-CISS)) and 
contrast-enhanced MR cisternography (CE-MRC) in detecting the localisation of 
cerebrospinal fluid (CSF) leak in patients with rhinorrhoea. 17 patients with 
active or suspected CSF rhinorrhoea were included in the study. 3D-CISS 
sequences in coronal and sagittal planes and fat-suppressed T1-weighted 
spin-echo sequences in three planes before and after intrathecal contrast media 
administration were obtained. Images were obtained of the cribriform plate and 
sphenoid sinus. In addition, high-resolution CT (HRCT) was performed in order to 
evaluate the bony elements. The leak was present in 9/17 patients with 3D-CISS 
and 10/17 patients with CE-MRC. The leak from the cribriform plate to the nasal 
cavity in six patients and from the sphenoid sinus in four patients was nicely 
shown by CE-MRC. Eight of those patients were surgically treated, but 
spontaneous regression of the symptoms in two precluded any intervention. The 
leak localisations shown with CE-MRC were fully compatible with surgical 
results. The sensitivities of HRCT, 3D-CISS and CE-MRC for showing CSF leakage 
were 88%, 76% and 100%, respectively. In conclusion, 3D-CISS is a non-invasive 
and reliable technique, and should be the first-choice method to localise CSF 
leak. CE-MRC is helpful in conditions when there is no leak or in complicated 
cases with a positive beta2-transferrin measurement.