Anatomo-radiological study of the superior semicircular canal dehiscence of 37 cadaver temporal bones

作者：Mondina Michel; Bonnard Damien; Barreau Xavier; Darrouzet Vincent; Franco Vidal Valerie^*

来源：Surgical and Radiologic Anatomy, 2013, 35(1): 55-59.

DOI：10.1007/s00276-012-0992-1

• Superior semicircular canal
• Dehiscence
• Computed tomography
• Poschl plane
• Stenvers plane

Purpose To assess the presence of dehiscence of the superior semicircular canal (SSCC) on computed tomography (CT) scanning and to study the microscopic anatomo-radiological correlation.
Materials and methods Thirty-seven temporal bones preserved in formalin, regardless of the clinical history of cadavers, were studied. A microscopic anatomical study was conducted with an operative microscope (209). The settings of the CT permitted to obtain 0.6 mm slices contiguous reconstruction in Poschl plane and in Stenvers plane. Three-dimensional (3D) reconstructions were performed if a radiological dehiscence was observed. The apex thickness was measured in Poschl plane. The radiological positive criterion of SSCC dehiscence was an absence of bone coverage of more than 1 mm long in Poschl and Stenvers planes.
Results We observed three dehiscences of the 37 temporal bones on CT in Poschl and Stenvers planes. However, no dehiscence was found microscopically. The 3D reconstruction was also positive in these three cases. Reconstructions in the Poschl plane offered good results up to a bone thickness of 0.6 mm. When it was lower than 0.6 mm, the interpretation of the images appeared to be subjective.
Conclusion This study emphasizes the limitations of CT imaging, with a risk of false positives to take into account when interpreting the images. The 3D reconstructions also give too many false positives to be used alone and make an accurate diagnosis. The diagnosis of SSCC dehiscence will therefore remain clinical. Complementary and instrumental radiological examinations should be performed only to confirm this clinical suspicion.

• 出版日期2013-1