Radiographic Assessment and Surgical Implications of Arcuate Eminence Pneumatization

Abstract

Background: The middle cranial fossa (MCF) approach is a valuable yet technically challenging technique. Identification of the superior semicircular canal (SCC) using the arcuate eminence (AE) was proposed as a surface landmark. However, the AE is sometimes absent, with inconsistent relationship to the SCC. Air cells in the AE area facilitate safer identification of the SCC. The aim of this study is to determine the radiographic prevalence of AE pneumatization. Methods: Two hundred consecutive fine-cut temporal bone CT scans were retrospectively reviewed. The region of the petrosal bone at and above the level of the SCC dome was assessed for the presence of air cells, and graded 0 (no pneumatization) to 2 (well pneumatized). Results: Four hundred temporal bones were studied. The average age was 49 years (range 18-89). Of all AE assessments, 47 (12%) were nonpneumatized, 62 (15%) partially pneumatized, and 291 (73%) well pneumatized. There was no significant correlation between patient age and pneumatization grade (p = 0.72). Conclusion: The SCC is a valuable landmark in MCF surgery as it holds consistent relationships to adjacent critical structures. Surrounding air cells should facilitate safer initial identification of the SCC, as the AE region is well pneumatized in 73% of patients.

Anatomical study between the correlation of the arcuate eminence and the superior semicircular canal

“…In our anatomical study, with radiological tests and subsequent dissection, we found that, in the prominent or very prominent Arcuate Eminence (1–2 mm and > 2 mm, respectively), corresponding to 74.6% of the eminences studied, the relief was due to pneumatization of this region, and in the flat ones (< 1 mm), it was due to protrusion of the semi-circular canal. These results are in agreement with those of Djallian [ 8 ], who stated that, in 79.6% of the arcuate eminences studied, the highest point corresponded to pneumatic cells, located above the semi-circular canal, as well as with the data described by Shoman [ 10 ], who observed pneumatization of the arcuate eminence area in 73% of the cases.…”

“…In c, d y e, as these cells originate from the attic of the tympanic cavity. AE arcuate eminence, IAC internal auditory canal, SSC superior semicircular canal, **** Tegmen tympani, TC tympanic cavity; Arrow: prolongation of cells from the attic; ** pneumatic cells canal, as well as with the data described by Shoman [10], who observed pneumatization of the arcuate eminence area in 73% of the cases.…”

“…Several hypotheses have been put forward in terms of the origin of the arcuate eminence. One of them suggests that it originates from the protrusion of the superior semi-circular canal [ 8 ], while others do not find a direct coincidence between the two structures, suggesting that the arcuate eminence may be due to pneumatization processes, or to the grooves that the temporal lobe of the brain leaves on the crest [ 9 , 10 ]. In our anatomical study, with radiological tests and subsequent dissection, we found that, in the prominent or very prominent Arcuate Eminence (1–2 mm and > 2 mm, respectively), corresponding to 74.6% of the eminences studied, the relief was due to pneumatization of this region, and in the flat ones (< 1 mm), it was due to protrusion of the semi-circular canal.…”

Extension of the Clinical Significance of the “Cog”

“…This could provide important anatomical parameters for facial nerve and temporal bone lateral skull base surgeries [2]. The use of CT imaging data for 3-D reconstruction to define the important structure of the human temporal bone, the structure of the middle skull base, and the facial nerve-related structures have a very high clinical significance [3][4][5][6].…”

Anatomic Study of Localization of Foramen Ovale, Carotid Canal, Jugular Foramen Using Henle’s Spine as Surface Landmark in South Indian Adult Skulls

“…It represents one of the latest surgical frontiers and poses surgical challenges for the otolaryngologists and the neurosurgeons. (1,2) Otologic and neurotologic skull base surgery requires a thorough knowledge of the temporal bone anatomy, as the temporal bone is one of the great gateways of the skull. (3) Its petrous portion gives the passage for the internal carotid artery, vestibulocochlear nerve and facial nerve.…”