鼻咽癌侵犯前中颅窝的MRI表现

目的探讨鼻咽癌向前、中颅窝侵犯的ＭＲＩ征象。方法回顾分析３９例有颅神经损伤并经病理确诊的鼻咽癌病例，用１．０Ｔ磁共振机，行头颅、鼻咽部轴位和冠状面Ｔ１ＷＩ、Ｔ２ＷＩ和矢状面Ｔ２ＷＩ扫描，应用钆喷替酸葡甲胺（ＧｄＤＴＰＡ）增强后，分别行轴位、冠状面、矢状面Ｔ１ＷＩ扫描。结果（１）前颅窝受侵１３例，筛窦受侵３例，眶尖、球后受侵４例，两者同时受侵６例。（２）中颅窝受侵３８例，蝶骨体破坏３２例，蝶窦肿块２５例，破裂孔异常２０例，卵圆孔异常２８例，蝶鞍破坏６例，海绵窦受侵３５例。结论鼻咽癌经破坏颅底骨质、进出颅腔的自然骨性通道和两者并存的３种途径向前、中颅窝侵犯，ＭＲＩ能准确显示侵犯途径和程度

MRI of nasopharyngeal carcinoma invading the anterior and middle cranial fossae

Objective To study MRI characteristics of nasopharyngeal carcinoma(NPC) with anterior and middle cranial fossa spread. Methods 39 cases of NPC with cranial nerve involvement were selected for this study. Axial and coronal T 1,T 2 weighted, sagittal T 2 weighted, and Gd DTPA enhanced MRI were performed. Results (1) 13 cases had frontal cranial fossa invasion. There were 3 cases with ethmoid sinus involvement.4 cases with orbital apex and postbulbar encroachment,6 patients with combined invasion. (2) 38 cases suffered from middle cranial fossa erosion. There were 32 cases with sphenoid bone destruction, 25 cases with tumor invading sphenoid sinus, 20 cases with foramen lacerum abnormality, 28 cases with foramen ovale abnormality, and 6 cases with sella turcica abnormality. Encroachment on cavernous sinus was found in 35 cases. Conclusions NPC may spread to the anterior and middle cranial fossae by destruction of skull bone, via anatomic bony foramina, or the combination of the two. These patterns could be accurately demonstratd by MRI.