From the case:
Otic capsule: annotated CT
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Annotated axial CT of the right petrous temporal bone:
- blue arrow: otic capsule (dense bone)
- yellow arrow: petrous apex
- orange arrow: mastoid air cells
- red arrow: cochlea
- green arrow: vestibule
Original case courtesy of Dr David van Gelderen, Radiopaedia.org, rID: 37030. Original file: http://radiopaedia.org/cases/normal-petrous-temporal-bone-axial-ct. Annotations: crop and arrows.
Case Discussion
Recognition of the otic capsule is important because its involvement in petrous temporal bone fractures increases the likelihood of serious complications. The otic capsule (blue arrow) is the dense bone (compared to the petrous apex and mastoid part) that surrounds the membranous inner ear structures.