原发性中枢神经系统淋巴瘤MRI诊断

MRI diagnosis of primary intracerebral malignant lymphoma

关键词:  脑肿瘤 ＭＲ  磁共振弥散加权成像  淋巴瘤

Key words:  brain neoplasm  magnetic resonance  diffusion-weighted imaging  lymphoma

摘要:

［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。

Abstract:

［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.［Conclusions］Primary intra-cerebral lymphoma has some special MR appearance and we can make correct diagnosis in most cases.