Abstract:

BACKGROUND: Distribution characteristics of round window and surrounding structures on cross section have been discussion in previous studies. Though the CT could identify the inner structures of temporal bone, its tiny parts could hardly be observed accurately and clearly by the imaging examinations of auriculotemporal portion.
OBJECTIVE: To compare and analyze the differences of the round window area of the temporal bone as well as the otology by coronal sections and high-resolution computed tomography (HRCT).
METHODS: The images of HRCT were obtained from 15 normal appearance cadaver heads (30 sides) which were scanned by a basic line that perpendicular to the canthomeatal line (CML). They were 1.0 mm in depth and 1.0 mm in thickness. The serial thin coronal sections which were 1.0 mm in thickness were made, taking the temporal bone as the centre. All the sections were taken from the structures in the temporal region, such as auditory ossicle, osseous semicircular canals, vestibule, cochlea, round window, round window niche, Prussak's space, and facial nerve. And finally such sections were compared with HRCT.
RESULTS AND CONCLUSION: The exterior and interior diameter and the depth average of round window niche was (1.36± 0.26) mm and (1.55±0.26) mm respectively. The distance from labyrinthine of facial nerve to arcuate eminence was (4.19± 0.52) mm. And the distance from horizontal segment of facial nerve to tegmen tympani, cochlea, head of malleus, scutal shield and short crus of incus was (5.27±0.92) mm, (1.36±0.28) mm, (3.19±0.85) mm, (5.30±0.58) mm and (2.86±0.54) mm respectively. Such collodion’s thin coronal section specimens of temporal bone could show the anatomical positions between round window area and its related structure well. Compared with the HRCT, the results contributed to the imaging diagnosis and the operations about the aural diseases.