鼻咽癌海绵窦侵犯的MRI评价

目的探讨鼻咽癌侵犯海绵窦的发生率、主要侵犯途径及MRI特点。方法经病理证实并经MRI检查的鼻咽癌患者141例,使用1．5T超导MR机进行检查,增强扫描前行快速自旋回波（FSE）序列横断面T1WI、T2WI扫描,增强后采用快速扰相梯度回波（FSPGR）脂肪抑制序列横断面及冠状面扫描。由两位经验丰富的放射科医师读片。结果141例患者中,有39例（49侧）海绵窦受侵犯,发生率为27．7％。卵圆孔为最常见的单一侵犯途径,有18侧仅通过卵圆孔侵犯海绵窦,占36．7％;多途径侵犯海绵窦的患者中,有6侧（12．2％）经卵圆孔与破裂孔侵犯海绵窦,为最常见共同途径。最常见的MRI表现为海绵窦增大伴异常强化（22侧）,其次为海绵窦壁局限性或弥漫性增厚和（或）海绵窦内血管、神经结构紊乱或模糊不清（18侧）,海绵窦局部形成肿块者9侧。结论卵圆孔是鼻咽癌侵犯海绵窦的主要途径。MRI能有效、准确地判断鼻咽癌侵犯海绵窦的情况,对指导临床采取正确治疗措施具有重要价值。

Evaluation of MRI in nasopharyngeal carcinoma with cavernous sinus infiltration

Objective To investigate the incidence, MRI characteristics and invasion route of nasopharyngeal carcinoma (NPC) infiltrating the cavernous sinus. Methods The data of 141 patients with histologically proven NPC collected from May 2003 to June 2004 were reviewed. All patients were examined by 1.5-tesla superconducting MR unit to evaluate the tumor extent. MR FSE technique was used for T1WI and T2WI images in the axial plane, followed by FSPGR fat-suppressed gadolinium-enhancement for T1WI images in the axial and coronal sections. All MR images were interpreted and evaluated by two diagnostic radiologists, paying particular attention to the nasopharynx and cavernous sinus infiltration. Results MR imaging showed infiltration of 49 cavernous sinuses in 39 patients (27. 7%). The most common MRI features were enlargement of cavernous sinus with unconventional enhancement (22/49, 44.9% ) , even with formation of mass inside the sinus (9/49, 18.4% ). The other MRI image features were local or diffuse dura mater thickening of cavernous sinus and presence of obscure structure as intra-sinus blurs and hazies inside. The most common infiltration route is through the foramen ovale ( 18/49, 36.7% ) , or through both the foramen ovale and foramen lacerum (6/49, 12. 2%). Conclusion In NPC patients, MRI invasion is characteristically and clearly shown as changes in the cavernous sinus. Possession of this information is crucial for giving correct treatment. The main infiltrtion route is through foramen ovale.