Assessment of the Anatomical Relationship Between the Arcuate Eminence and Superior Semicircular Canal by Computed Tomography

Abstract

The anatomical relationship between the arcuate eminence (AE) and the superior semicircular canal (SSC) was examined by computed tomography (CT) in 52 petrous bones of 26 patients. After acquiring volume data by multidetector CT, 1-mm thick oblique bone window images perpendicular to the SSC were obtained from the axial images. The distances between the AE and the SSC, and the SSC and the superior surface of the petrous bone were measured. The AE corresponded exactly with the SSC in only 2/52 petrous bones, and corresponded well in 7/52. The AE was lateral to the SSC in 25/52 cases, medial to the SSC in 6/52 cases, intersected in 3/52 cases, and was indiscernible in 9/52 cases. The distance between the SSC and the petrous surface was 0 mm in 45/52 petrous bones, 1 mm in 5/52, 2 mm in 1/52, and 3 mm in 1/52. The SSC typically does not correspond exactly with the AE, and is generally located just under the surface of the petrous bone. Planning of the middle cranial fossa approach requires location of the SSC by CT.

Sectional Anatomy of the Petrous Bone for the Study of the Ear

“…The arcuate eminence is considered an eminence on the superior surface raised by the SSC [2][3][4]. But many studies have found it to be not directly over the SSC [5][6][7][8]. In the present study the SSC was found to lie rather anterior to the arcuate eminence.…”

The Predictability Precision of Superior Semicircular Canal Through Radiological Assessment and Microanatomical Dissection

“…In the present study, a great majority of the attached copper wires (13 of 24) was found to be localized posterolateral to the SSC. Seo et al [3] reported lateral location as 25/52 in their series [2] . High variability of AE with respect to SSC is documented by very low percentages of complete correspondence of these two anatomic structures.…”

“…Although AE is shown to exist in 100% of all neonates, this proportion is reported as 70% in the adult population. This eminence is more often seen on the left side compared with right and reported to be invisible approximately in 25% of cases [3] .…”

“…High variability between these two anatomic structures is reported by various studies in the related literature [3][4][5] . Radiological or microanatomical dissection studies are performed to better delineate the relationship of AE and the SSC [6,7] .…”

Links Between Surgical Landmarks of the Temporal Bone and Cochlear Implant Approaches

“…Other authors also measured the angles described by the corners of the triangle, therefore we did not consider necessary to repeat those measurements [5].…”