Detection of perilymphatic fistula in labyrinthine windows by virtual endoscopy and variation of reconstruction thresholds on CT scan

{Background: Perilymphatic fistula (PLF) is a breach in a labyrinthine window. The opening might decrease the radiological density of the window. Aims/objectives: To evaluate the radiological density of the labyrinthine windows by virtual endoscopy on CT scan. Materials and methods: This prospective study included 47 adult patients with PLF and 98 control patients. Diagnosis of PLF was based on a composite radio clinical score and/or intra operative visualization of the fistula and/or resolution of the symptoms after surgery. On routine CT-scan, labyrinthine windows were examined by virtual endoscopy. The reconstruction threshold was gradually increased until a virtual opening appeared (opening threshold [OT]) and compared to the contralateral window (OT difference). Results: The OT difference was higher in patients than in controls (60.2 +/- 10.36 (SEM)