[A three-dimensional quantitative measurement related to sigmoid sinus by using multi-slices spiral CT].

Objective: To provide a valuable imaging anatomic method for operation of the posterior transpetrosal approach and accurate positioning among relative structures in order to reduce the incidence of surgical complications.

Methods: The clinical information of 119 adult cases (238 sides) was analyzed. All the cases underwent 16 layer helix CT scanning and three-dimensional image reconstruction of skull base without a skull base disease.