Role of 3D CT in the Evaluation of the Temporal Bone

Abstract

In recent years, three-dimensional (3D) multiplanar reformatted images from conventional cross-sectional computed tomographic (CT) data have been increasingly used to better demonstrate the anatomy and pathologic conditions of various organ systems. Three-dimensional volume-rendered (VR) CT images can aid in understanding the temporal bone, a region of complex anatomy containing multiple small structures within a relatively compact area, which makes evaluation of this region difficult. These images can be rotated in space and dissected in any plane, allowing assessment of the morphologic features of individual structures, including the small ossicles of the middle ear and the intricate components of the inner ear. The use of submillimeter two-dimensional reconstruction from CT data in addition to 3D reformation allows depiction of microanatomic structures such as the osseous spiral lamina and hamulus. Furthermore, 3D VR CT images can be used to evaluate various conditions of the temporal bone, including congenital malformations, vascular anomalies, inflammatory or neoplastic conditions, and trauma. The additional information provided by 3D reformatted images allows a better understanding of temporal bone anatomy and improves the ability to evaluate related disease, thereby helping to optimize surgical planning.

Syndromes of the First and Second Branchial Arches, Part 1: Embryology and Characteristic Defects

“…Middle ear defects can be subtle or severe and include absent or maldevelopment of any of the ossicles, with alteration of other structures of common embryologic origin (such as the course of the facial nerve) (Fig 5). 12,[31][32][33] Jahrsdoerfer et al 34 described a 10-point rating scale for the selection of surgical candidates by comparing high-resolution CT findings with postsurgical hearing results. Using 9 reproducible criteria, one calculates a score to predict postoperative improvement of the speech-reception threshold ( Table 2).…”

Which temporal bone anatomical structures and pathologies could be best visualized by applying reconstruction to cross-sections obtained on an axial plane?

“…In addition, temporal bones contain functional spaces, plurality of holes, and channels through which blood vessels and nerves pass. [1,4] At the end of the 1950s when politomography became more common, temporal bone imaging emerged as a specialized area within radiology departments. The recommended tube angulation during assessment of the temporal bone varies depending on the region examined, but in daily use, standard techniques include axial and coronal projections.…”

CT Findings in the External Auditory Canal after Transcanal Surgery

“…At the medial end of the EAC is a rise in the floor of the EAC adjacent to a narrow furrow, the tympanic sulcus. [12][13][14] Surgery is widely used to treat various middle ear conditions, including inflammatory disease, congenital malformations, trauma, and tumors. 4,5 Surgical approaches to the middle ear through the EAC may involve drilling the bony EAC walls to provide adequate exposure.…”