原发性脑淋巴瘤与脑转移瘤的MRI鉴别诊断

The differential diagnosis of MRI imaging features for primary malignant lymphomas and metastases in brain

目的对照分析脑内原发性恶性淋巴瘤和脑转移瘤的MRI不同表现特点。方法回顾分析经病理证实的脑内原发性恶性淋巴瘤25例、肺癌脑转移瘤119例的MRI资料,所有病例均行MRI平扫及增强检查。结果前者单发18例(72%),多发7例(28%),幕上33例,幕下4例,MRI平扫T1WI呈边缘模糊的等或稍低信号,T2WI呈高信号,增强均见肿瘤均匀或不均匀强化,瘤周多为轻、中度水肿,占位效应轻,出血少见。后者单发43例(36%),多发76例(64%),脑内血行播散灶258个,幕上和脑干216个,幕下42个,MRI平扫为T1WI低信号,T2WI高信号,增强可见环形、结节状强化,中、重度水肿,占位效应明显,可见出血和坏死。结论脑内原发性恶性淋巴瘤与脑转移瘤影像表现各具特征性,但相互间具较多交叉,仔细分析能提高今后诊断准确性。

Objective To analysis the MRI features of primary MRI brain lymphoma and brain metastases. Methods The MRI data of 144 cases diagnosed as primary brain lymphoma or brain metastases by surgery or biopsy were analyzed retrospectively. All the cases were performed by MRI plain scan and enhanced scan. Results Primary brain lymphoma which was included 18 cases with single lesion and 7 cases with multiple lesions. The lesions of 33 cases distributed insupratentorium, of 4 cases in inferior tentorium. On MRI： Low or equal signal on T1WI and hyper signal on T2WI were appeared. Homogeneous or inhomogeneous enhancement presented in most of the tumors. Most lymphomas in brain showed minimal or moderate edema. Brain metastases with 43 single lesion and 76 cases with multiple lesions. Theses lesions have ring shaped enhancement. Conclusion The imaging finding of primary brain lymphoma and brain metastases have different characteristics, but they have many overlaps. By analysis the features of lymphoma, the accuracy of diagnosis will be improved in the future.