Loke S C, Goh J P N
Department of Diagnostic Radiology, Tan Tock Seng Hospital, Jalan Tan Tock Seng, Singapore.
Br J Radiol. 2009 May;82(977):371-3. doi: 10.1259/bjr/32471003. Epub 2008 Dec 19.
Semicircular canal dehiscence is a congenital syndrome that mainly affects the superior and, less commonly, the posterior semicircular canals. The diagnosis of superior semicircular canal dehiscence syndrome depends on the demonstration of a very small defect in the bony wall of the superior semicircular canal. Any amount of intact bone present excludes the diagnosis. The study will give an approximation of the incidence of semicircular canal dehiscence in Singapore. No specific data regarding the number of such cases exist currently. Retrospective review of CT scans of the temporal bone performed at our institution between January 2005 and July 2007 revealed a total of 10 such cases over this period, comprising 8 males and 2 females, with all cases involving the superior semicircular canal. Almost all of the patients scanned had evidence of previous or existing cholesteatoma. Three patients had bilateral superior semicircular canal dehiscence (all males), with an almost equal number of semicircular canal dehiscence on both sides for both sexes. Our study shows no significant advantage to obtaining reformatted oblique sagittal images for all temporal bone studies, unless the visualized walls show questionable defects. In these cases, reconstructed images are probably advantageous and should be obtained and reviewed.
半规管裂是一种先天性综合征，主要影响上半规管，较少影响后半规管。上半规管裂综合征的诊断取决于上半规管骨壁上一个非常小的缺损的显示。只要有任何数量的完整骨质存在，即可排除诊断。本研究将给出新加坡半规管裂的发病率近似值。目前尚无关于此类病例数量的具体数据。对2005年1月至2007年7月在我们机构进行的颞骨CT扫描进行回顾性分析发现，在此期间共有10例此类病例，其中男性8例，女性2例，所有病例均累及上半规管。几乎所有接受扫描的患者都有既往或现患胆脂瘤的证据。3例患者为双侧上半规管裂（均为男性），男女两侧半规管裂的数量几乎相等。我们的研究表明，对于所有颞骨研究，除非所显示的骨壁有可疑缺损，否则获取重组斜矢状位图像并无显著优势。在这些情况下，重建图像可能具有优势，应该获取并进行评估。
