低场MRI在鼻咽癌诊断中的应用

Low field MRI on the diaguesis of nasopharynsed carcinoma（NPC）

目的分析鼻咽癌的MRI表现，探讨低场MRI在鼻咽癌诊断中的应用。方法回顾性分析我院83例经病理活检证实的鼻咽癌MRI表现。结果鼻咽癌的主要MRI表现：鼻咽顶后壁及左侧壁、右侧壁粘膜增厚或局部软组织肿块形成，咽隐窝表浅、消失，咽鼓管咽口变钝或闭塞，咽旁间隙移位或变窄、消失，一侧或双侧中耳乳突炎症，可伴颅底骨破坏，并侵犯海绵窦、眼眶、颞下窝或翼腭窝受累及。瘤体组织T1WI呈均匀等信号或稍低信号，T2WI呈均匀稍高信号或较高信号，增强扫描肿瘤呈重度、中等度、轻度强化分别为22（31．0％）例、41（57．7％）例、8（11．3％）例。结论低场MRI能多方位清楚、准确地显示鼻咽癌的部位、大小、形态、侵犯范围及周同组织结构受累程度，是临床诊断鼻咽癌最优良的影像检查方法。

Objective The MRI manifestdtions of NPC were analysed and low-field MRI on the diagnosis of NPC was disscussed.Methods The MRI manifestations cf 83 casea that were confirmed by biopsy were analysed retrospectively.Results The MRI of NPC manifese mainly as follow：The mucosa thickened or soil tissue mass formed on the top of posterior, left and right nasopharyngeal wall, Pharyngeal recess became supperficial and disappearing, And pharyngeal ostium of eustachian tube became dull or bstructive, The pharyngeal space displaced or narrowed and disappeared, unilteral or bilateral otomastoiditis can be seen and can be accompanied by the destruction of skull base, carernous sinus and orbit can be violated, and temporal fossa or pterygopalatine fossa can be involed .The T1WI signal of tumorous tissue was homogeneous or slightly low, the T2WI signal was slightly high or higher on the enhamced scanning, the amount（or ratio） of serer, moderatc and mild enhanced cases were respectively 22 （31.0%）, 41（57.7%）, 8 （ 11.3% ）. Conclusions Low-fild MRI can imdicate muticfaceted clearly and accurately the location,size, shape, violating scope of NPC and the extent of involting adjacent tissue and structure, So the low-fild MRI is the best imaging examination on the diagnosis of NPC.