[Study on the incidence and characteristics of carotid canal dehiscence with high resolution CT]

Objective:To discuss the total incidence and characteristics of carotid canal dehiscence in Chinese adults with high resolution CT. At the same time, it provide basic data for otology clinical medical personnel to further understand the anatomical structure of ear and carry out auditory surgery.Method:Temporal bone HRCT images of 643 consecutive subjects who underwent CT scanner were analyzed retrospectively. The coronal, sagittal, and oblique sagittal plane were reconstructioned for some suspected subjects. Contrast the incidence of carotid canal dehiscence in different sex, bilateral and age groups.Result:In 643 patients, 43 cases found the carotid canal dehiscence, and the total incidence of carotid canal dehiscence was 6.7%.The incidence of carotid canal dehiscence for male and female were 5.9%(16/269)and 7.2%(27/374)(P > 0.05),and there was no statistically significant difference in the incidence of carotid canal dehiscence between sexes. The incidence of carotid canal dehiscence for age 40-59 was much higher than those of other age groups (P< 0.05),however, there was no significant difference between groups of age 20-39 and ≥60(P> 0.05).The location of the carotid canal dehiscence in 43 cases was located in the mesotympanum near the Eustachian tube orifice. Carotid artery tube ruptures are mostly small defects, but 11 cases with major defect.Conclusion:The toatal incidence of carotid canal dehiscence is 6.7% in Chinese adults (males: 5.9%,females: 7.2%), especially high incidence at group of age 40-59 (10.7%). Carotid canal dehiscence can be diagnosed accurately by HRCT and multiplanar reconstruction.