Objective: Application of technique of high resolution CT (HRCT) and multipliate plane reconstruction, analyzed the image features of suspicious superior semicircular canal dehiscence (SSCD) to improve the understanding of the SSCD.Method:From January 2016 to April 2017, a total of 230 adult patients who checked temporal bone HRCT were collected in this retrospective study, of which 160 cases (320 ears) of the non-SSCD, 73 cases were male (146 ears), 87 cases were female (174 ears), aged 18 to 70 years old; 70 cases (113 ears) were suspicious diagnosed with SSCD, 33 cases were male (55 ears), 37 cases were female (58 ears), and 18 to 71 years old. The thin section CT scan of the temporal bone translocation was performed on all subjects, then the CT post processing workstation was used for multipliate plane reconstruction (MPR), and the main rows of coronal and oblique sagittal image reconstruction was performed. To observe, measure and record the HRCT features and datas of the suspicious SSCD and non-SSCD, then analyze the collected data.Result:There were 160 cases (320 ears) in non-SSCD group, and the height of the superior semicircular canal was (6.43±0.51)mm, the outer tube diameter was (0.83±0.13)mm, the thickness of the tympanic cavity was (2.19±0.62)mm, the anteroposterior diameter of mastoid was (14.55±1.98)mm; There were 70 cases (113 ears) in the suspicious SSCD group, the above results were (6.42±0.60)mm, (0.85±0.16)mm, (1.62±0.55)mm, (13.24±1.97)mm, respectively. Statistical analysis showed that there were no significant difference in the height of the superior semicircular canal (P=0.94) and the outer tube diameter (P=0.64), There were significant differences in the thickness of the tympanic cavity (P=0.002) and the anteroposterior diameter of mastoid (P=0.004). There were 70 cases (113 ears) in group suspicious SSCD, the unilateral defect had 27 cases (27 ears), and bilateral defect had 43 cases (86 ears). The defect was located in the middle of the parietal wall in 48 ears, located in the anterior wall of 20 ears, located in the posterior wall of 32 ears, more than two defects in 13 ears; 7 ears were mastoid pneumatic type, 90 ears were mastoid sclerotic type, 16 ears were mastoid mixed type.Conclusion:The SSCD was more common in the sclerotic mastoid. The bilateral defect was common, mostly located in the middle of the parietal wall. The occurrence of the lesion is not related to the height and diameter of the superior semicircular canal, but may be related to the thinning of the whole temporal bone.
Keywords: high resolution CT; multipliate plane reconstruction; superior semicircular canal dehiscence, , ,; temporal bone.