耳蜗植入中平片的作用

The Role of Plain Radiograph for Cochlear Implantation

目的:为观察电子耳蜗植入后的形态、位置和深度,选择一种合适的影像技术。方法:将多通道模拟人工耳蜗电极,由耳科医生植入8个尸头的15个耳蜗内,分别拍摄经眶前后位、侧位、耳蜗位X线片,并做颞骨高分辨计算机断层扫描(HRCT)。6位病人植入相同规格的人工耳蜗电极,并拍摄耳蜗位X线片。结果:所有正侧位X线片均能显示耳蜗内植入的电极,但不能显示其在耳蜗内的确切位置。HRCT图像只能显示部分电极,却无法区别单个电极的形态。耳蜗位X线片不仅可见螺旋形排列的电极走向,而且能辨认前庭和后半规管的形态,并可以此为标记划出参考线,以帮助计算耳蜗内电极的深度。4例标本5例病人有效电极全部进入耳蜗内,其余植入的电极数在12～20之间。将由耳蜗位X线片算得与手术中数得电极数进行比较,平均符合率达97.46%;6例完全一致,准确率28.57%(6/21例)。结论:耳蜗位X线片可充分满足耳蜗植入术后检查的需要。

Objective:The aim of this study is to establish a suitable techniq ue for the assessment of the postoperative appearance,position and insertion de pth of the electrode array. Methods:An electrode of the Nucleus multichannel co chlear implant was inserted into the 15 cochlear of 8 cadaveric skulls. Radiogra phs were obtained in Anterior-Posterior (AP) per-orbital projection,lateral v iew,cochlear view and HRCT.The cochlear implant insertion of the same device in 6 patients were also studied. Postoperative digital radiographs of these patien ts were obtained in cochlear view.All radiolographic findings were evaluated wit h the surgical estimated insertion depth.Results:The AP and lateral projection plain radiolographs could show the intracochlear electrode array but could not t ell the correct electrode placement.HRCT could show only a part of the electrode array,but individual electrodes could not be clearly distinguished. In a cochl ear view radiograph,the inserted electrodes were seen as a spiral within the co chlea both in cadaveric skulls and in patients. The vestibule(V) and superior se micircular canal(SSC) could also be recognized and form important landmarks for drawing a reference line to calculate the number of electrodes within the cochle ar.The completely inserted electrodes were seen in 4 cadaveric skull and 5 patie nts.In the rest,the insertion depth ranged from 12 to 20 electrodes.There was a high correlation between the radiologic and surgical results with regard to the number of electrodes inserted.Conclusion:A postoperative cochlear view is suff icient because it can serve as a result of operation,a baseline for further rad iographic examination and a valuable reference for further research purpose.