Division of Neurosurgery, Toronto Western Hospital and University of Toronto, Toronto, Ontario, Canada.
Neurosurgery. 2011 Apr;68(4):1077-83. doi: 10.1227/NEU.0b013e31820c6cbe.
Preservation of cranial nerves (CNs) is of paramount concern in the treatment of vestibular schwannomas, particularly in large tumors with thinned and distorted CN fibers. However, imaging of the CN fibers surrounding vestibular schwannomas has been limited with 2-dimensional imaging alone.
To assess whether tractography of the CN combined with anatomic magnetic resonance imaging of the tumor can provide superior 3-dimensional (3D) visualization of tumor/CN complexes.
Magnetic resonance imaging at 3 T, including diffusion tensor imaging and anatomic images, were analyzed in 3 subjects with vestibular schwannomas using 3D Slicer software. The diffusion tensor images were used to track the courses of trigeminal, abducens, facial, and vestibulocochlear nerves. The anatomic images were used to model the 3D volume reconstruction of the tumor. The 2 sets of images were then superimposed through the use of linear registration.
Combined 3D tumor modeling and CN tractography can effectively and consistently reconstruct the 3D spatial relationship of CN/tumor complexes and allows superior visualization compared with 2-dimensional imaging. Lateral and superior distortion of the trigeminal nerve was observed in all cases. The position of the facial nerve was primarily anteriorly and inferiorly. The gasserian ganglion and early postganglionic branches could also be visualized.
Tractography and anatomic imaging were successfully combined to demonstrate the precise location of surrounding CN fibers. This technique can be useful in both neuronavigation and radiosurgical planning. Because knowledge of the course of these fibers is of important clinical interest, implementation of this technique may help decrease injury to CNs during treatment of these lesions.
在治疗前庭神经鞘瘤时，保护颅神经（CNs）至关重要，尤其是在 CN 纤维变薄和变形的大型肿瘤中。然而，仅通过二维成像，对前庭神经鞘瘤周围 CN 纤维的成像受到限制。
评估 CN 束追踪与肿瘤的解剖磁共振成像相结合是否可以提供肿瘤/CN 复合体的卓越三维（3D）可视化。
使用 3D Slicer 软件对 3 名前庭神经鞘瘤患者的 3T 磁共振成像（包括扩散张量成像和解剖图像）进行分析。使用扩散张量图像追踪三叉神经、展神经、面神经和前庭耳蜗神经的路径。使用解剖图像对肿瘤的 3D 体积重建进行建模。然后通过线性配准将这两组图像叠加。
3D 肿瘤建模和 CN 束追踪的组合可以有效地一致重建 CN/肿瘤复合体的 3D 空间关系，并提供优于二维成像的可视化效果。所有情况下均观察到三叉神经的侧向和上方扭曲。面神经的位置主要在前下方。也可以看到神经节和节后早期分支。
成功地将束追踪和解剖成像相结合，以展示周围 CN 纤维的精确位置。该技术在神经导航和放射外科规划中都很有用。由于了解这些纤维的走向具有重要的临床意义，因此实施该技术可能有助于减少这些病变治疗过程中对 CNs 的损伤。
