原发性中枢神经系统淋巴瘤的MRI与~1H-MRS研究

目的:探讨免疫功能正常人原发性中枢神经系统淋巴瘤(PCNSL)的常规MRI及多体素质子磁共振波谱(1H-MRS)表现。方法:对15例经病理证实的PCNSL的MRI和1H-MRS表现进行回顾性分析。结果:15例患者共检出24个病灶,其MRI及1H-MRS表现如下:①PCNSL的MRI表现:病灶T1WI呈低或等信号,T2WI呈等或稍高信号;DWI呈高信号;增强后病灶明显均匀强化,"缺口征"、"尖角征"的出现具有特异性;②PCNSL的1H-MRS表现:肿瘤实质区及瘤周近侧水肿区Cho峰升高及NAA、Cr峰降低,肿瘤实质区可见升高的Lip峰。4例病灶在正常组织区可见异常谱线。结论:传统MRI结合1H-MRS表现能够显著提高PCNSL的诊断与鉴别诊断水平;1H-MRS对于肿瘤浸润及多发病灶的显示优于传统MR检查。

The MRI and 1H-MRS study of primary central nervous system lymphomas (PCNSL)

Objective：To discuss MRI and 1H-MRS findings of PCNSL in immunocompetent patients. Methods：MRI and 1H-MRS findings in 15 patients with pathologically proved PCNSL were analyzed retrospectively.Results：24 lesions were identified in 15 patients.The MRI and 1H-MRS findings of PCNSL were as folows：① MRI findsings：Hypo or isointensity on T1-weighted images and iso-hyperintensity on T2-weighted images,and hyperintensity on DWI; enhancement was intensive and homogeneous,the presence of ＂incision sign＂ and ＂angular sign＂ were more specific; ② MRS findings：Spectrum of PCNSL in all cases were similar with Cho peak increased in the parenchyma and surrounding edematous region while Cr and NAA peak decreased. Prominent peak of lipid can be seen in parenchyma. In 4 cases,abnormal spectrum were found in nomal region. Conclusion：Conventional MRI combined with MR spectrum can improve diagnostic and differential diagnotic accuracy of PCNSL. MR spectrum （1H-MRS） possessess some advantages over conventional MR in the diagnosis of peripheral tumor cell infiltration and multifocal PCNSL.