原发性中枢神经系统淋巴瘤的磁共振成像表现

目的探讨原发性中枢神经系统淋巴瘤（PCNSL）的磁共振成像（MRI）特征及鉴别诊断。方法回顾性分析15例经手术病理证实的PCNSL的MRI表现。结果病理检查均为B细胞来源的弥漫性大B细胞性淋巴瘤。15例PCNSL19个病灶，单发13例（87％），多发2例（13％）共6个病灶。病灶常位于脑表浅部位和近中线部位，T1wI呈等或稍低信号，T2WI及液体衰减反转恢复序列（FLAIR）呈等或稍高信号，弥散加权成像（DWI）呈高信号。所有病灶均明显强化，增强后病灶大多呈均匀实质团块状或结节状强化，典型的可出现“尖角征”、“握拳征”，3例可见小囊变，呈“硬环征”。结论PCNSL的MRI表现具有一定的特征性，术前MRI检查有助于诊断及鉴别诊断，结合患者影像学及临床资料，术前可作出明确诊断。

MRI appearances of primary central nervous system lymphoma

Objective To explore the MRI appearances and the differential diagnosis value of the primary cen tral nervous system lymphoma（PCNSL）. Methods MRI appearances of 15 patients with PCNSL which were proven by surgery and pathological examination were analyzed retrospectively. Results All patients were confirmed as the diffuse larger B-cell lymphoma pathologically. Nineteen lesions were identified in 15 patients, 13 （87%） were identi fied to have solitary tumor loci and the other 2 （13%）presented a multifocal form with a total of 6 lesions. Most le- sions were located near the surface or middle line of brain. On T1WI, the lesions showed isointensity or hypointensity. On T2WI or FLAIR images, most lesions presented isointensity or slightly hyperintensity. On DWI, the lesions present ed hyperintensity. All lesions were enhanced markedly, the typical cases presented in cision sign and angular sign, es- pecially for these lesions adjacent to the subarachnoid space. Three lesions were showed microcystic foci and the presence of ring sign after gadolinium in jection. Conclusion The MRI appearance of PCNSL has the specificity. Preoperative MRI is helpful for the diagnosis and differential diagnosis. Correct diagnosis could be made before oper ation when imaging findings are considered together with clinical data.