影像学在人工耳蜗植入术中的价值

人工耳蜗移植术(CI)是帮助双侧重度、极重度感音性耳聋病人改善听力和语言交流能力的一种有效手段。术前了解耳蜗及内耳神经纤维的结构与病变情况,比较双侧内耳神经的残存功能,选择合适的植入耳,对手术的成功至关重要。就不同影像技术在CI术前评估中的价值作一综述。     

影像学在人工耳蜗植入术中的价值

人工耳蜗移植术(CI)是帮助双侧重度、极重度感音性耳聋病人改善听力和语言交流能力的一种有效手段.术前了解耳蜗及内耳神经纤维的结构与病变情况,比较双侧内耳神经的残存功能,选择合适的植入耳,对手术的成功至关重要.就不同影像技术在CI术前评估中的价值作一综述.     

多通道人工耳蜗植入术的影像评估

目的：探讨影像学检查对人工耳蜗植入术的评估价值。资料与方法：对52例感音性耳聋患者均采用颞骨轴位高分辨率螺旋CT扫描及内耳三维重建和内耳MR水成像。术后常规行耳蜗位摄影，3例术后行CT扫描。结果：41例先天性感音耳聋患儿中检出1例2耳Mondini畸形I型，3例6耳Mondini畸形Ⅱ型，1例2耳耳蜗纤维化；5例非先天性器音耳聋患儿未发现内耳结构畸形。另6例语后聋成人中检出1例2耳慢性化脓性中耳炎，1例2耳内耳骨化。耳蜗位摄影对植入电极观察满意，CT检出1例术后植入电极扭结。结论：对于人工耳蜗植入术的术前评估，CT检查具有重要价值，必不可少；MRI检查是必要的补充。对于内耳的三维重建，MRI优于CT。对术后植入电极的评估，耳蜗位摄影最佳。     

人工耳蜗植入术前的影像学评估

目的分析人工耳蜗植入(CI)术前颞骨MRI及CT表现,并探讨术前影像学对人工耳蜗植入的价值。方法拟行CI的160例患者均行高分辨率CT扫描,64例同时行横、冠状面扫描,119例行MR检查。结果320耳乳突均气化良好,乳突蜂房向后超过乙状窦前壁206例。左、右侧乳突长度分别为(2.34±0.42)、(2.25±0.40)mm(U=1.887,P<0.05),宽度分别为(1.57±0.30)、(1.50±0.27)mm(U=2.35,P<0.05)。中耳炎8耳,CT示鼓室及乳突蜂房不含气,MRI为长T1,长T2信号。颈静脉球窝扩大或高位18耳,蜗窗龛狭窄2耳。迷路炎9耳,8耳CT表现耳蜗、半规管及前庭不同程度的骨化,MRI表现为长T1,短T2及短T1、等T2信号,并且T2WI信号不连续。1耳膜迷路闭塞,CT为阴性,MRI表现为等T1、等T2信号。耳蜗完全未发育1耳,耳蜗发育周数不足6耳,Mondini畸形5耳。前庭导水管扩大40耳,前庭、半规管发育畸形10耳,内耳道狭窄5耳。结论术前的颞骨影像学诊断,对于CI成功实施能够提供重要信息。     

电子耳蜗植入的影像学评价

综述了影像学检查对电子耳蜗植入术前和术后的评价，分别介绍了CT、MRI和常规X线在其评价中的应用研究及临床价值。     

MR内耳水成像在儿童人工耳蜗植入术前评估中的价值

目的：探讨MR内耳水成像在儿童人工耳蜗植入术前评估中的临床应用价值。方法使用Siemens Avanto 1．5 T磁共振扫描仪对24例听觉障碍拟行人工耳蜗植入术的患儿进行扫描,采集内耳所在区域内的水信号,并送后处理工作站进行图像后处理。最后分析其影像学表现及特征。结果24例患者中内耳形态正常18例,耳蜗发育畸形伴前庭导水管扩张1例,单纯前庭导水管扩张3例,半规管异常1例,Mondini畸形1例。结论 M R内耳水成像技术能清晰显示内耳膜迷路以及内听道精细解剖结构,对于内耳病变的诊断及人工耳蜗植入术的术前评估提供重要信息。     

影像学检查与耳蜗移植

耳蜗植入装置是一种模拟耳蜗功能的换能器，它将声音信号转变成电信号，通过植入内耳的电极，绕过耳蜗内丧失功能的感觉细胞直接兴奋听神经，从而产生听觉。术前了解耳蜗及内耳神经纤维的结构与病变情况，比较双侧内耳神经的残存功能，选择合适的植入耳，对耳蜗移植手术的成功至关重要。随着现代影像学的发展，影像学检查在耳蜗移植术前术后的评估、选择合适的患者和移植耳中发挥着越来越重要的作用。不同的现代影像学技术能被用来作为耳蜗移植     

改良的耳蜗后前位DR在耳蜗植入术中的临床应用

目的评价改良的耳蜗后前位数字化X线摄影(DR)在耳蜗植入术中的应用价值。方法 30例内耳疾病或感音性聋患者(男17例,女13例,年龄17 d～45岁,平均6岁)均在人工耳蜗植入术后,接受了改良的耳蜗后前位DR。结果改良的耳蜗后前位DR能清晰显示植入耳蜗的电极串整个形态及位置,电极的数目及深度,并能辨认前庭和上、外半规管的形态。与传统的X线摄影比较,改良的耳蜗后前位DR可使头颅摆位更加简便,从而简化操作步骤,缩短曝光时间,减小患者的辐射剂量,同时,能明显地提高图像质量。结论改良的耳蜗后前位DR比传统X线摄影具有明显优势,在人工耳蜗植入术中有广阔的应用前景。     

儿童人工耳蜗植入术前的影像学评估

分析先天性感音神经性聋患儿人工耳蜗植入术前颞骨高分辨率CT与MRI表现,探讨其应用价值。对78例感音神经性聋患儿行术前的高分辨率CT以及其中68例另行MRI,对61例患儿术后6个月进行听力学评估随访。内耳发育畸形共21例:其中耳蜗不发育1例;MondiniI型1例;单纯MondiniII型1例;前庭导水管扩大14例,其中合并MondiniII型5例,合并半规管发育不良1例;内听道狭窄伴前庭耳蜗神经发育不良1例;半规管发育不良2例,其中1例伴内听道扩大;脑脊液内耳漏1例。术后随访结果提示:耳蜗神经发育不良者听力无明显改善,Mondini畸形者的预后较大前庭导水管综合征者及无特殊畸形者差。CT能显示外耳、中耳及内耳骨迷路解剖,MRI则能显示包括膜迷路在内的内外淋巴液,同时还可显示内听道内前庭蜗神经,而耳蜗神经的存在是CI手术的必要条件,不同类型的内耳畸形与预后之间可能存在一定相关性。     

人工耳蜗植入一例报告

随着人工耳蜗技术的日渐成熟,人工耳蜗植入已得到了较为普遍的开展,这为一些深度感音神经性耳聋患的听功能恢复提供了一个新的途径。日前我们为1名大前庭水管综合征伴有重度感音神经性耳聋及言语发育障碍的患成功地实施了人工耳蜗植入手术,现报告如下。     

Role of high resolution CT and radiography in postoperative evaluation of cochlear implantation

Objective

To assess the role of HRCT and Radiography in postoperative evaluation of cochlear implants.

Patients and methods

Radiography; including Stenver’s and modified Chause III positions, as well as HRCT were carried out in 12 patients with cochlear implants. HRCT images were obtained utilizing 0.625 mm slice thickness followed by reconstruction using 0.3-mm reconstruction increment and high-resolution algorithm.

Results

On HRCT, complete insertion of electrode array was noted in one patient, incomplete insertion in two and partial insertion in nine patients. The position of the electrode array as compared to CT and radiography revealed agreement in 11 patients; and disagreement in one. The radiologic position of the electrode array was compared to intra-operative electrophysiological testing and surgical data. In three patients, there was agreement. In one patient, contacts 11 and 12 were nonfunctioning with good impedance and were extra-cochlear. One patient had nonfunctioning contact 12 with high impedance and absent stapedial reflex and was extra-cochlear. In one patient, contacts 11 and 12 showed high impedance and were extracochlear. In nine patients, intra-operative electrophysiological testings were satisfactory with three having high impedance of last contact. Facial twitches were encountered in two patients.

Conclusion

Technological advances will expand the applications of HRCT in cochlear implant recipients.     

Digital imaging: a valuable technique for the postoperative assessment of cochlear implantation

Cochlear implantation with a multi-channel electrode array which provides stimulation via the auditory nerve has become a standard treatment for profound deafness. Postoperative radiography demonstrates electrode position and enables confirmation of satisfactory intra-cochlear electrode placement. The number of active electrodes which have been inserted can be determined and possible complications such as electrode kinking or slippage can be assessed. We evaluated digital radiography with confirmation of electrode position by intermittent fluoroscopy and assessed the relative radiation dose of the digital technique, conventional radiography and CT scanning. Radiation dose for this method usually ranges between 40 μGy and 440 μGy compared with a single exposure on the skull stand which produces a dose to the region of the cochlea of 470 μGy and a CT exposure of 950 μGy. The digital technique is comfortable for the patient, easily reproducible and provides images of high diagnostic quality enabling each electrode to be identified, which is especially valuable in association with postoperative electrode mapping. It also involves a lower radiation dose than conventional radiography. We now use digital radiography for all postoperative cochlear implant assessment. Received 13 March 1997; Revision received 17 September 1997; Accepted 21 January 1998     

颞骨MSCT及多种后处理技术在婴幼儿人工耳蜗植入术中的临床应用

目的 探讨颞骨多层螺旋CT(MSCT)及多种后处理技术在婴幼儿人工耳蜗植入术中的临床应用价值.方法 对50例术前和2例术后重度感音神经性耳聋(SNHL)患者行颞骨高分辨率CT平扫,应用双斜径多平面重建、面神经曲面重建、双阈值重建+透明成像+三维融合等后处理技术,对鼓岬平面面神经垂直段与外耳道后壁的距离、圆窗宽度进行测量及对内耳结构进行分析.结果 ①50例术前患者中,内耳发育畸形7例,发病率为14.0％(7/50);慢性中耳乳突炎9例;另34例内耳、乳突未见明显异常.50例术前患者均清晰重建出内耳、听骨链三维结构,精确测量出鼓岬平面双侧面神经垂直段与外耳道后壁的距离[右侧(0.33±0.057) cm、左侧(0.33±0.068) cm]及双侧圆窗宽度[右侧(0.14±0.027) cm、左侧(0.14±0.025) cm],完整显示出面神经走行路径.②2例术后复查患者均清晰显示出电极位置及术后改变情况.结论 部分先天性SNHL存在内耳发育畸形,颞骨MSCT高分辨扫描能清晰显示内耳畸形,同时应用多种后处理重建及测量技术,可为婴幼儿人工耳蜗植入术前提供更精确的颞部解剖影像信息和术后评估.     

Postural disorders induced by cochlear implantation in normo-reflexic patients: A potential origin of a transient geocentric perception disorder

BackgroundProfound hearing loss is a public health problem with serious consequences for patient's quality of life. Some of them, submitted to cochlear implantation, revealed various postural disorders such as balance and spatial perception disorders without detail on their vestibular status.Research questionThe purpose of this preliminary study was to analyze the evolution of the balance control and geocentric perception after cochlear implantation procedure in normo-reflexic patients before the implant activation.MethodsWe assessed balance control of five patients with profound hearing loss and five healthy participants by means of computerized dynamic posturography and their geocentric perception by the subjective visual vertical test before surgery, three days and forty-five days after surgery (prior to implant activation).ResultsBefore surgery, the patients showed some difficulties to control their balance in challenged postural context without geocentric perception disorder. Patients presented an improvement in their postural accuracy, but their balance control remained inappropriate in challenging environment. Moreover, their geocentric perception was deviated towards their healthy ear immediately after cochlear implantation. This misperception naturally fades before the implant activation.SignificanceThis transient spatial perception alteration might probably cause the perceived postural discomforts and the daily difficulties often reported by these patients in their clinical records early after cochlear implantation. This preliminary study allows for the first time the distinction between the both components of posture: balance control and geocentric perception. Therefore, a specific therapeutic care targeting the rehabilitation of spatial cognition could be proposed to these patients in order to reduce their transient postural disorders.     

儿童人工耳蜗植入术作CT扫描时眼球的放射防护

目的优化儿童人工耳蜗植入术前、后作颞骨CT扫描的曝光参数，减少其辐射危害。方法对疑有颞骨内耳病变者87例（其中人工耳蜗植入手术接受者31例），行颞骨薄层高分辨CT扫描（HRCT），以成人扫描参数为标准，适当调整扫描曝光量及扫描角度，直至图像符合诊断的要求，并分析其曝光量及单次扫描的加权CT剂量指数（CTDIw）和剂量长度乘积（DLP）。结果儿童颞骨CT扫描曝光量及单次扫描的CTDIw值可降低到成人曝光量的66．67％～83．33％，DLP也可降低到66．67％～83．33％，且内耳及植入电极三维重建图像质量优良。结论儿童人工耳蜗植入术前、术后作CT扫描曝光量的适当降低，以及扫描角度的适当调整，可有效地降低颞骨局部的辐射剂量，且有效地避免了儿童眼晶体的直接辐射伤害。