颅内三叉神经鞘瘤的影像学分析

目的评价颅内三叉神经鞘瘤的CT和MRI诊断价值。方法回顾分析16例经手术和病理证实的颅内三叉神经鞘瘤的CT和MRI资料，9例行CT扫描，8例行MRI扫描。结果颅内三叉神经鞘瘤分三型：颅后窝型（4例）、颅中窝型（3例）及骑跨型（9例）；CT扫描肿瘤呈混杂密度、均无钙化；可见岩尖骨质吸收或破坏（4例）。肿瘤MRI T1WI呈低信号，T2WI呈高信号，增强扫描实性病灶呈均匀强化，囊变（6例）病灶呈环状强化。结论CT和MRI能较准确地显示肿瘤部位、形态、内部结构和增强表现，对颅内神经鞘瘤的诊断及鉴别诊断具有重要价值，MRI对神经鞘瘤的定性诊断准确性优于CT。

CT and MRI diagnosis of intracranial trigeminal schwannoma

Objective To investigate the diagnostic value of CT and MRI on intracranial trigeminal schwannoma. Methods CT and MRI findings of 16 patients with intracranial trigeminal schwannoma confirmed by pathology were analyzed retrospectively, including 9 case of CT, 8 case of MRI. Results Intracranial trigeminal schwannoma was divided into three types： posterior cranial fossa type （4 cases）, middle cranial fossa type （3 cases）, and transcranianial fossa type （9 cases）. CT features of the tumors included mixed density, no calcification, petrous apex bone resorption or destruction （n=4）. The tumors demonstrated as low-signal intensity on MR T1-weighted images, and high signal intensity on T2-weighted images, with heterogeneous enhancement after Gd-DTPA injection. Cystic degeneration was occurred in 6 cases, with ring-like enhancement after Gd-DTPA injection. Conclusion CT and MRI can accurately show the tumor site, shape, internal structure and enhancement performance. CT and MRI have a great diagnostic and differential diagnostic value in intracranial trigeminal schwannoma. MRI is better than CT in qualitative diagnosis of trigeminal schwannoma.