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Background
Accurate diagnosis of temporal bone pathologies requires detailed knowledge of its anatomy. However, learning temporal bone anatomy continues to pose challenges to many radiologists, especially to those currently in training. One reason for this is that the temporal bone contains many complex structures, many of which are not always well-imaged using the conventional CT technique. Therefore, the purpose of this educational exhibit is to (1) review the complex anatomy of the temporal bone using images from micro-CT scan of cadaveric studies and (2) review the characteristic CT findings of some temporal bone pathologies.

Educational Goals / Teaching Points
The educational goals of this exhibit is to emphasize the relationship between structures and structures that are usually not well-imaged on conventional CT technique, and define the characteristic CT findings, and variant presentations of these temporal bone conditions: pars flaccida cholesteatoma, labyrinthitis ossificans, paraganglioma (glomus tympanicum), fenestral and retrofenestral otosclerosis, endolymphatic sac tumor, genicular ganglion hemangioma, and meningioencephaloceles.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Prussak space, pars flaccida of the tympanic membrane, middle ear ossicles, fissula ante fenestram, oval window, stapedius muscle, pyramidal eminence, sinus tympani, facial recess, vestibule, semicircular canal. Pars flaccida cholesteatoma, labyrinthitis ossificans, paraganglioma (glomus tympanicum), fenestral and retrofenestral otosclerosis, endolymphatic sac tumor, genicular ganglion hemangioma, and meningioencephaloceles. Soft tissue mass in the Prussak space, erosion of scutum, ossicular erosion, retraction of the pars flaccida, ossification of the inner ear structures (cochlea, vestibule, semicircular canals). High-resolution micro-CT scanner with a resolution of 7 µm.

Conclusion
Using high-resolution images obtained from micro-CT scan of a cadaveric temporal bone, we successfully demonstrated many complex structures that are not always well-imaged on conventional CT. Using these images, we hope to educate the readers about temporal bone anatomy and the many pathologies affecting it. Specifically, we will focus on clinical pathologies that require detailed knowledge of the anatomy to arrive at the correct diagnoses.