Evaluation of MR Cisternography in Diagnosis of Cere- brospinal Fluid Fistula
Lojana Tuntiyatorn MD*, Jiraporn Laothammatas MD*
Affiliation : * Department of Radiology, Faculty of Medicine Ramathibodi Hospital, Mahidol University
Purpose : To study the clinical usefulness and sensitivity of MR cisternography as noninvasive study in the
diagnosis of CSF fistula in patients with clinical diagnosis CSF rhinorrhea or otorrhea.
Method : Thirty-five patients with clinically diagnosed CSF leakage were examined for site of dural tear
with MR cisternography with additional plain high-resolution CT in some cases from Jan. 1999 to Dec.2002.
The MR imaging technique was performed as a heavily T2 weighted fast spin echo study with fat suppression
in axial, coronal and sagittal projections. Criteria for positive results were demonstrable fistular tract
connecting subarachnoid space to paranasal sinus/petrous bone, and/or dural discontinuity, and/or bone
defect with pneumocephalus, and/or presence of brain herniation. Eighteen of the patients subsequently had
exploratory surgery for fistula. Sensitivity analysis of the surgical results was compared with the findings at
MR cisternography.
Result : MR cisternography showed significant correlation with surgical findings with sensitivity of 89%.
Additional high resolution CT were complete agreement with site of fistular tract. The pathogenesis of CSF
leakage was related to trauma (86%). The commonly found dural/bony defect and location of connecting
fistular tract were cribriform plate and ethmoid sinus of 58%, 55% respectively.
Conclusion : In the presence of clinically diagnosed CSF leakage, the combination of MR cisternography
and plain high-resolution CT are highly accurate in locating the site and extent of CSF fistula and should be
considered a viable noninvasive alternative to CT cisternography and Tc-99m-DTPA cisternography.
Keywords : CSF fistula, CSF rhinorrhea, CSF otorrhea, MR cisternography
