原发性中枢神经系统淋巴瘤MRI诊断

MRI diagnosis of primary intracerebral malignant lymphoma

[目的]探讨原发性脑内中枢神经系统淋巴瘤的传统MRI及弥散加权成像(DWI)影像学特征。[方法]回顾性分析21例经病理证实的脑内原发性淋巴瘤的MRI影像学表现,10例进行了传统MRI平扫、增强及DWI扫描。11例仅进行了常规MRI扫描。[结果]21例患者单发肿瘤15例(71.40%),多发肿瘤6例(28.6%),共31个病灶,27个病灶位于大脑(87.1%),3个位于小脑(9.7%),1个位于下丘脑(3.2%)。病灶T1WI、T2WI信号与脑灰质相近。所有病灶都有占位效应,水肿程度不一。所有病灶都呈明显强化,囊变区无强化。7个病灶(22.6%)中心见裂隙状低信号影,周围呈环带状明显强化区。10例共13个病灶进行了DWI扫描,所有病灶在DWI图像呈明显高信号,ADC图呈低信号。[结论]脑内淋巴瘤MRI表现具有一定特征性,结合传统MRI及DWI检查有助于该疾病的明确诊断。

[ Objective] To investigate conventional MRI and diffusion - weighted MR images（DWI） features of primary intracerebral lymphoma. [ Methods] MR images were reviewed retrospectively in 21 patients with pathologically proved primary intra- cerebral lymphoma. Both conventional plain and contrast MRI and DWI scanning were performed in 10 patients,while only conventional MRI scanning was performed in 11 patients. [ Results ] A total of 31 lesions were present in 21 patients; 6 patients （28.6%） had multiple lesions. 27 （87.1%） of the lesions were located in the cerebral hemisphere and 3 lesions （9.7%） were located in the Cerebellum and the rest one lesion （3.2%） was located in the hypothalamus. The signals of all lesions were homogeneous and similar to grey matter on both T1 and T2 - weighted images except one with a small cyst formation. Mass effect and edema surrounding the lesion can be seen in all the cases. All the lesions were strongly enhanced after the injection of the contrast medium. A fissure low signal in the centre and surrounding high signal area can be seen in 22.6% （7 lesions） of all the foci. Additional DWI scanning was taken in 10 cases with 13 lesions. All the foci were hyper signal on DWI and low signal on ADC map. [ Conclusion ] Primary intra - cerebral lymphoma has some special MR appearance and we can make correct diagnosis in most cases.