Taoka Toshiaki, Hirabayashi Hidehiro, Nakagawa Hiroyuki, Sakamoto Masahiko, Myochin Kaoru, Hirohashi Shinji, Iwasaki Satoru, Sakaki Toshisuke, Kichikawa Kimihiko
Department of Radiology, Nara Medical University, Nara, and Higashiosaka City General Hospital, Osaka, Japan.
J Magn Reson Imaging. 2006 Nov;24(5):1005-10. doi: 10.1002/jmri.20725.
To preoperatively visualize the course of the facial nerve, which is displaced by vestibular schwannoma, using diffusion tensor (DT) tractography, and to evaluate the agreement with surgical findings.
The subjects were eight patients with vestibular schwannoma who had undergone removal surgery. DT MR images were obtained and tracts that were considered to represent the facial nerve were constructed. We assessed the success rate for tract construction and evaluated the agreement between tractography findings and surgery.
We obtained a tract that connected the internal auditory meatus and brainstem, and was considered to represent the facial nerve in seven of eight cases. The course of the constructed tract agreed with surgical findings in five of these seven cases. One exception was a case in which the tumor was too large to enable intraoperative observation of the facial nerve; however, the facial nerve appeared to be displaced anteriorly at intracapsular resection, in agreement with tractography. In the other case, the schwannoma was mostly cystic.
Tractographs constructed using MR tensor images enabled us to identify tracts considered to represent facial nerves. We consider DT tractography to be a useful tool for preoperatively predicting facial nerve displacement in vestibular schwannoma.
利用扩散张量（DT）纤维束成像术前可视化被前庭神经鞘瘤移位的面神经走行，并评估其与手术结果的一致性。
研究对象为8例接受了切除手术的前庭神经鞘瘤患者。获取DT磁共振图像并构建被认为代表面神经的纤维束。我们评估了纤维束构建的成功率，并评价了纤维束成像结果与手术之间的一致性。
我们在8例中的7例中获得了一条连接内耳道和脑干且被认为代表面神经的纤维束。在这7例中的5例中，构建的纤维束走行与手术结果一致。一个例外是肿瘤过大以至于术中无法观察到面神经的病例；然而，在囊内切除时面神经似乎向前移位，这与纤维束成像结果一致。另一例中，神经鞘瘤大部分为囊性。
利用磁共振张量图像构建的纤维束成像使我们能够识别被认为代表面神经的纤维束。我们认为DT纤维束成像对于术前预测前庭神经鞘瘤中面神经的移位是一种有用的工具。
