Skull base tumors such as meningiomas and schwannomas are often pathologically benign. However, surgery for these tumors poses significant challenges because of their proximity to critical structures such as the brainstem, cerebral arteries, veins, and cranial nerves. These structures are compressed or encased by the tumor as they grow, increasing the risk of unintended injury to these structures, which can potentially lead to severe neurological deficits. Preoperative imaging is crucial for assessing the tumor size, location, and its relationship with adjacent vital structures. This study reviews advanced imaging techniques that allow detailed visualization of vascular structures and cranial nerves. Contrast-enhanced computed tomography and digital subtraction angiography are optimal for evaluating vascular structures, whereas magnetic resonance imaging (MRI) with high-resolution T2-weighted images and diffusion tensor imaging are optimal for evaluating cranial nerves. These methods help surgeons plan tumor resection strategies, including surgical approaches, more precisely. An accurate preoperative assessment can contribute to safe tumor resection and preserve neurological function. Additionally, we report the MRI contrast defect sign in skull base meningiomas, which suggests cranial nerve penetration through the tumor. This is an essential finding for inferring the course of cranial nerves completely encased within the tumor. These preoperative imaging techniques have the potential to improve the outcomes of patients with skull base tumors. Furthermore, this study highlights the importance of multimodal imaging approaches and discusses future directions for imaging technology that could further develop preoperative surgical simulations and improve the quality of complex skull base tumor surgeries.
颅底肿瘤如脑膜瘤和神经鞘瘤在病理上通常为良性。然而，由于这些肿瘤邻近脑干、脑动脉、静脉及颅神经等关键结构，其手术切除面临重大挑战。随着肿瘤生长，这些重要结构会受到压迫或包裹，从而增加术中意外损伤的风险，可能导致严重的神经功能缺损。术前影像学评估对于判断肿瘤大小、位置及其与邻近重要结构的关系至关重要。本研究综述了能够清晰显示血管结构和颅神经的先进影像技术：增强计算机断层扫描和数字减影血管造影最适合评估血管结构，而高分辨率T2加权磁共振成像及扩散张量成像则最适用于评估颅神经。这些方法有助于外科医生更精确地规划肿瘤切除策略，包括手术入路选择。准确的术前评估有助于实现安全切除肿瘤并保护神经功能。此外，我们报道了颅底脑膜瘤的MRI对比剂缺损征，该征象提示颅神经穿行于肿瘤内部。这对于推断完全被肿瘤包裹的颅神经走行具有重要意义。这些术前影像技术有望改善颅底肿瘤患者的预后。本研究还强调了多模态影像方法的重要性，并探讨了影像技术的未来发展方向，这些技术可能进一步推动术前手术模拟的发展，提升复杂颅底肿瘤手术的质量。
Preoperative Vascular and Cranial Nerve Imaging in Skull Base Tumors
肿瘤(癌症)患者之家