Semicircular Canal Dehiscence: Imaging, Diagnosis, Classification, Surgical Options, and Postoperative Imaging

Since the association of sound- and/or pressure-induced vertigo and dehiscence of the superior semicircular canal was first described in 1998, imaging studies have been increasingly performed to exclude semicircular canal dehiscence in patients with “dizziness.” This article will first discuss normal semicircular canal bony roof development and then review the theorized pathophysiology, clinical signs and/or symptoms, and audiology examination findings of semicircular canal dehiscence. Semicircular canal dehiscence CT and MR imaging techniques and findings are reviewed. A semicircular canal dehiscence imaging classification system is proposed, which provides a standardized methodology for the interpretation and reporting of semicircular canal dehiscence imaging studies. Also, superior and posterior semicircular canal dehiscence surgeries and postoperative imaging findings are discussed.

Learning Objective: To identify and characterize deficiencies in the semicircular canal bony roofs using CT and MR imaging to review the clinical presentation and treatment options for patients with semicircular canal dehiscence syndrome and to discuss superior semicircular canal dehiscence postoperative imaging.