![]() ![]() CT temporal bone studies on additional scanners were excluded if a slice thickness of <= 1 mm was not available. ĬT studies/patients with intrinsic bone disease, prior labyrinthine surgery or petrous bone trauma on the basis of the clinical request and report were excluded from either search.Ĩ6.5% of search 1 and 86.9% of search 2 of high-resolution CT temporal bone studies were performed on a single scanner (Philips Brilliance 40, Philips, the Netherlands mA 100, kV 120, FOV 180 mm, matrix 768 × 768, pitch 0.348, slice thickness 0.67 mm, reconstruction index 0.33 mm). All grades of OS in the Symons/Fanning classification were included in the study, with the group of pericochlear OS patients corresponding to Symons/Fanning classification grades 2 and 3. Where there was CT evidence of OS, images were evaluated for the presence of both fenestral (“fenestral OS”) and pericochlear disease (“pericochlear OS”). The second search, which identified cases with OS, collated CT temporal bone studies performed over a 6-year period between 20 those containing the terms “otosclerosis” or “otospongiosis” in the report or request text were further assessed to confirm the diagnosis of OS. The first search, which identified cases without OS, collated consecutive CT temporal bone studies performed over a 2-year period between 20 those with radiological evidence of OS in either temporal bone were excluded on the basis of the report and subsequent imaging review. Two separate searches of the radiology information database were performed (CRIS, Healthcare software solutions ltd, Mansfield, UK). This was a retrospective study performed in a tertiary centre and was approved by the institutional review board without the requirement for informed consent. There are no clear audiometric implications of these morphological features. IAC diverticula associated with pericochlear OS demonstrate different morphological features from isolated IAC diverticula. No morphological feature was associated with conductive hearing loss in isolated diverticula or with sensorineural hearing loss in diverticula with fenestral OS alone. Reduced neck:depth ratio, ill definition and angulation were all significantly associated with the presence of pericochlear OS ( p < 0.001), whilst only ill definition was associated with the presence of fenestral OS alone ( p < 0.05). Ninety-five isolated IAC diverticula were demonstrated in 54/978 patients (5.5%) without CT evidence of OS (31M, 23F, mean age 46), and 119 IAC diverticula were demonstrated in 71/306 patients (23%) with CT evidence of OS (23M, 48F, mean age 55). Continuous data was compared using Wilcoxon rank sum tests and categorical data with chi-squared and Fisher’s exact tests. Audiometric profiles were analysed for the isolated IAC diverticula and those with fenestral OS alone. Two independent observers evaluated the presence of IAC diverticula morphological features (depth, neck:depth ratio, definition of contour and angulation of shape), and these were correlated with the presence of fenestral and pericochlear OS. MethodsĬonsecutive temporal bone CT studies with ( n = 978) and without ( n = 306) features of OS were retrospectively assessed. We explored whether isolated IAC diverticula were morphologically different from those with additional CT features of OS, and whether IAC diverticula morphology influenced patterns of hearing loss. The association of internal auditory canal (IAC) fundal diverticula with otospongiosis (OS) and their clinical significance remain unclear. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |