脑内原发性淋巴瘤的MRI诊断

Magnetic resonance imaging diagnosis of primary lymphoma in the brain

目的回顾性分析脑内原发性淋巴瘤MRI特点及病理改变,旨在提高对该病的MRI诊断水平。方法分析17例经手术病理证实的脑内原发性淋巴瘤的MRI表现,并与病理结果对照分析。结果(1)单发或多发病灶靠近中线区或脑表面,多发病灶占59%,易侵及额顶叶白质、胼胝体及基底节区;(2)T1WI呈低或稍低信号17例,T2WI呈等信号或稍高信号14例,占82%,坏死及出血少见;(3)灶周水肿及占位效应以轻度到中度为主;(4)强化方式以“握拳”样或团块状显著均匀强化为主,肿瘤可沿脑脊液播散。结论脑内原发性淋巴瘤的MRI表现具有一定的特异性,多数情况下综合分析可在术前作出正确诊断,但需与脑内多种疾病相鉴别。

Objective To study retrospectively the MRI features and pathological findings of primary lymphomas in the brain for increasing diagnosis accuracy. Methods MRI and pathological findings of 17 cases of primary lymphoma in the brain were comparatively studied retrospectively. Results Seventeen patients presented a single lesion in 7 cases （41% ） and multiple lesions in 10 cases （59 % ）. The common sites were white matter of the frontal and parietal lobe, corpus collusum and the basal ganglia. The lesions showed hypointensity or mildly hypointensity on TtWI in 17 cases and iso - intensity or slightly hyperintensity on T2WI in 14 cases （82 % ）. Necrosis and hemorrhage were rarely seen. Most lesions showed mild to moderate peritumoral edema and mass effect. On enhanced T1WI, majority displayed markedly homogeneous enhancement,sometimes lesions spread along CSF. Conclusion MRI findings of primary lymphomas in the brain have some characteristics. It is possible to make preoperative diagnosis in most cases of primary lymphomas, however differentiate diagnosis should be considered in atypical cases.