Published in:
01-04-2020 | Tinnitus | Otology
CT and MRI for the diagnosis of perilymphatic fistula: a study of 17 surgically confirmed patients
Published in: European Archives of Oto-Rhino-Laryngology | Issue 4/2020
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Background
We evaluated the usefulness of CT and MRI for the diagnosis of perilymphatic fistula (PLF) of the round (RW) and/or oval (OW) windows, with surgery as gold standard.
Methods
We retrospectively enrolled 17 patients who presented a surgically confirmed PLF of the round (RW) or oval (OW) windows. All patients were imaged by CT + MRI (T2W SSFP without contrast) prior to surgery (= gold standard). Two radiologists, analyzed the RW and OW on the side of the clinical symptoms and sensitivity (Se) + Specificity (Sp) were calculated.
Results
Round window fistula was the most frequent (71%). The best sign of PLF on imaging was a fluid filling of the window niches, which had good Se (83–100% for RW, 66–83% for OW) and Sp (60% for RW, 91–100% for OW). Disorientation of the footplate and pneumolabyrinth were also only observed in 50% of OW PLF.
Conclusion
The combination of CT and MRI is a reliable tool for a fast and accurate diagnosis of round and oval window perilymphatic fistula, with good sensitivity (> 80%). The most common sign of PLF on imaging is the presence of a fluid-filling in the RW (especially if > 2/3 of the RW niche) or in the OW niches on both CT and MRI. A disorientation of the footplate or the presence of a pneumolabyrinth are clearly in favor of an oval window perilymphatic fistula.