MDCT对耳硬化症术前评估的探讨

目的评估MDCT在术前耳硬化症诊断中的作用。方法收集经手术病理证实为耳硬化症、且CT扫描采用螺旋模式的病例共15例。扫描层厚为0.625mm,进床速度为1.2mm/rot,螺距为1:1。双侧分别小视野骨算法重建,重建视野为9.6cm,重建层厚为0.625mm,重建间隔为0.2mm。结果15例共30耳显示异常。仅前庭窗异常14耳,表现为前庭窗扩大或狭小。前庭窗及蜗窗同时受累共6耳。主要累及耳蜗周围迷路骨质10耳,表现为耳蜗骨迷路边缘不整,呈条片状密度减低或双环状改变。MPR交互重建充分显示了所有重要解剖结构的位置、形态:其中3耳为颈静脉球高位;所有病例均无面神经管水平段低位及面神经管裂,均无蜗导水管扩大及颈静脉球或颈动脉管裂。结论MDCT可以正确诊断耳硬化症,MPR重建可充分显示颞骨解剖及变异,有利于制定正确的手术计划。

MDCT in the preoperative evaluation of otosclerosis

Objective An evaluatation of the preoperative MDCT in the diagnosis of otosclerosis.Methods In total 15 patients with otosclerosis,confirmed by operation underwent MDCT examination.Scan slice thickness was 0.625 mm,table speed was 1.2 mm/rot and pitch was 1:1.The target temporal bone was reconstructed using a small FOV bone arithmetic method.Reconstructed field of view was 9.6 cm;reconstructed slice thickness was 0.625 mm;and reconstructed interval space was 0.2 mm.Results All 30 temporal bones were revealed abnormal.14 ears manifested enlargement or narrowness of vestibular window only.6 ears had abnormalities in vestibular and cochlear windows simultaneously.Abnormal bone labyrinth around the cochlea was found in 10 ears,which exhibited striped decreased attenuation or double circle alternation,with irregular margin.In 3 ears,high-riding jugular bulb was found.None of the 15 cases displayed low or dehiscent facial nerve canal,large vestibular aqueduct,dehiscent jugular bulb or carotid canal.Conclusion MDCT with MPR imaging correctly show the abnormalities of otosclerosis as well as the anatomy of the temporal bone.