目的探讨鼻咽癌咀嚼肌间隙侵 犯的MR特点。方法 回顾性分析经病理确 诊的442例初诊无远处转移鼻咽癌患者的 临床及影像资料，根据中国鼻咽癌临床分 期工作委员会制定鼻咽癌2008年分期方 案标准，将其中101例咀嚼肌间隙侵犯的 鼻咽癌患者资料纳入本研究。结果 442 例鼻咽癌患者中，咀嚼肌间隙侵犯101例 (22.8%)，咀嚼肌间隙侵犯途径及各部分 受侵情况呈由内向外侵犯，按侵犯部位分 布，其中翼内肌侵犯87例(19.6%)，翼外 肌及以外间隙侵犯48例(10.8%)，侵犯颞 肌3例(0.7%)，咬肌1例(0.2%)。咀嚼肌间 隙中单独侵犯翼内肌病例53例，7例为单 纯侵犯翼外肌病例。结论 MRI能清晰显示 鼻咽癌侵犯咀嚼肌间隙的范围，有助于准 确分期、精确勾画靶区。充分认识咀嚼肌 间隙结构特点及其MR表现，对指导鼻咽癌 的临床治疗意义重大。

Objective To investigate the MR features of masticator space involvement in NPC. Methods From July 2009 to December 2012, all the biopsy—proven newly diagnosed non-metastatic NPC 442 patients were collected, The clinical and imaging data of all cases were analyzed, and according to The Chinese 2008 staging system for NPC, The 101 cases with masticator space involvemen of NPC patients included in this study. Results In 442 cases of NPC patients , 101 cases (22.8%) were invasion of masticator space. Research showed that masticator space was violated from the inside to the outside. 87 cases (19.6%)were the medial pterygoid muscle involvement, 48 cases (10.8%)with the lateral pterygoid muscle and outside involveent, 3 cases (0.7%)with temporal muscle involvement , 1 cases (0.2%) of masseter muscle involvement. 53 cases were Singly the medial pterygoid muscle involvement,7 cases of simple violations of the lateral pterygoid muscle. Conclusion MRI can clearly show the range of nasopharyngeal carcinoma with masticator space involvement,and help us accurate staging and precise outline target. Fully understanding the masticator space structure characteristics and performance of MR is great significance for the clinical treatment in nasopharyngeal carcinoma.