关键词:  , 弓状隆起；　上半规管；　Fisch法；　CT三维成像

Abstract: Objective　 To explore how to locate the internal auditory canal through the middle cranial fossa approach, focus on the identification of the arcuate eminence and the relationship between the arcuate eminence and the superior semicircular canal in Fisch’s method.　Methods　Sixty subjects aged 18~57 years without space occupying lesions in the petrous part of the temporal bone were selected for bilateral measurement (totaling 120 sides). Among them, half were male and half female. The temporal bone was scanned by CT and the three-dimensional coordinate system was established to measure the three-dimensional coordinate values of the arcuate eminence and the superior semicircular canal.　Results　The shape of the arcuate eminence was uncertain: about 15% of the samples had no obvious arcuate eminence structure, which led to the inability to locate it. The arcuate eminence did not correspond strictly to the superior semicircular canal. About 83% of the samples had the arcuate eminence located in the posterolateral part of the superior semicircular canal.　Conclusion　In internal auditory meatus surgery by Fisch's method, there are some difficulties in identification of the arcuate eminence. Most of the superior semicircular canals are not always below the arcuate eminence, but located posterolaterally to the arcuate eminence.

Key words: Arcuate eminence;　Superior semicircular canals;　Fisch's method; ,  , Three-dimensional imaging in CT