多平面重组技术评价上半规管裂综合征

CT multiplan reconstruction images of superior semicircular canal dehiscence syndrome

目的探讨多平面重组（multi—planarreformation，MPR）技术在上半规管裂综合征中的诊断价值。方法收集2004年12月至2008年6月共9例临床诊断为上半规管裂综合征患者的颞骨常规高分辨率CT横断位、冠状位以及上半规管MPR的图像数据，层厚和层间距均为0．75mm，由三位放射科医师对上半规管的显示情况进行分析比较，探讨MPR技术在诊断上半规管裂中的优势。结果9例患者共18个上半规管中有9个患侧，在MPR图像上均可见明确的部分骨壁缺损，敏感性为100％；而在常规横断位和冠状位图像上明确显示骨壁缺损的分别只有7个和8个，敏感度依次为77．8％和88．9％。另外9个健侧的上半规管在MPR图像上均显示骨壁连续完整，但在横断位和冠状位图像上均有2个显示为骨壁缺损，其特异性均为77．8％。结论高分辨率CT扫描后行MPR技术的图像在上半规管裂综合征的诊断中较常规的横断位和冠状位图像具有更大的价值。

Objective To evaluate the clinical application of multi-planar reformation （MPR） for the diagnosis of superior semicircular canal dehiscence syndrome. Methods A retrospective study was conducted on 9 patients who were diagnosed with SSCD syndrome in the Otology and Skull Base Surgery group of Fudan University. Three radiologists analyzed all the patients＇ 0. 75 mm-collimated axial and coronal images and 0. 75 mm-eollimated MPR images, and they came up with the same results. Results There were 18 superior semicircular canal in the 9 patients, of whom 9 were intact and 9 were defective. All the defective superior semicircular displayed a definite dehiscence in all the MPR images, which indicated the sensitivity was 100% ; however, 7 of the 9 defective superior semicircular canal were diagnosed as dehiscence in axial images, while 8 of the 9 were diagnosed in coronal images, but the sensitivities were 77. 8% and 88. 9% respectively. The results of the other 9 with intact superior semicircular canal displayed in the MPR, axial, and coronal images were also different. In the MPR images, they all displayed definite intact roof over the superior semicircular canal. There were 2 dehiscence in all axial and coronal images, and the specificities were 77.8%. Conclusion The MPR image is more useful in diagnosis of superior semicircular canal dehiscence syndrome than that of the routine axial and coronal images.