Dept of ORL, HNS, University of Freiburg, Killianstrasse 5, 79106 Freiburg, Germany.
Hear Res. 2010 May;263(1-2):191-7. doi: 10.1016/j.heares.2009.12.003. Epub 2009 Dec 5.
A large air-bone-gap after ossiculoplasty may be due to a malpositioned or displaced prosthesis. Rotational tomography (RT) has the potential to provide high-resolution images of implants without artifacts and with less radiation dosage than CT scan. Twenty-seven temporal bone specimens underwent measurements of middle ear transfer function using Laser-Doppler-Vibrometry (LDV) before and after placement of ossicular replacement prostheses (PORPs, TORPs) made of titanium. RT was performed on all specimens. RT allowed 3-dimensional viewing of the temporal bone, accurate localization of implants within the reconstructed middle ear and determination of angles between the inserted prostheses and the tympanic membrane (TM) and/or the malleus handle (MH). Presence or absence of contact between the implant and the TM, malleus or stapes could be clearly visualized. Displaced prostheses were readily identified. The functional LDV-measurements for TORPs showed a trend favoring coupling to the malleus handle, while for PORPs, coupling to the TM was favored. For PORPs, sound transmission was worse with increasing angles between the PORP and stapes superstructure (p<0.05). Following our experimental results RT is an innovative, relevant and useful imaging technique to obtain immediate postoperative feedback after ossicular reconstruction and to precisely determine the position of middle ear implants.
鼓室成形术后出现大的气骨导间距可能是由于假体位置不当或移位。旋转断层扫描（RT）具有提供无伪影的高分辨率植入物图像的潜力，并且辐射剂量比 CT 扫描少。27 个颞骨标本在放置钛制听骨置换假体（PORP、TORP）前后使用激光多普勒测振仪（LDV）进行中耳传递函数测量。所有标本均进行 RT。RT 允许对颞骨进行三维观察，在重建的中耳内准确定位植入物，并确定插入的假体与鼓膜（TM）和/或锤骨柄（MH）之间的角度。可以清楚地看到植入物与 TM、锤骨或镫骨之间是否存在接触。移位的假体很容易被识别。TORP 的功能性 LDV 测量结果显示出有利于与锤骨柄耦合的趋势，而对于 PORP，则有利于与 TM 耦合。对于 PORP，随着 PORP 和镫骨上结构之间的角度增加，声音传输会变差（p<0.05）。根据我们的实验结果，RT 是一种创新的、相关的和有用的成像技术，可在鼓室重建后获得即时的术后反馈，并精确确定中耳植入物的位置。
