磁共振在脑内环形强化病变鉴别诊断的价值

The Value of MRI in the Differential Diagnosis of Circular Enhanced Brain Lesions

目的分析脑内环形强化病灶MR征象,探讨高级别胶质瘤、转移瘤、脑脓肿鉴别诊断要点及鉴别诊断价值。方法回顾性分析50例经活检、手术病理证实和经临床治疗及影像随诊证实的脑内表现为环形强化病变的MRI资料。结果高级别胶质瘤15例,转移瘤20例,脑脓肿15例。(1)高级别胶质瘤病变范围广泛,13例(86.6%)侵犯胼胝体;形态不规则,多房征,多发壁结节;12例(80.0%)DWI病变边缘模糊呈"晕"征,壁内呈低信号。(2)转移瘤形态规则、病变范围局限呈类圆形,壁边界清晰,瘤病灶小,位于皮髓交界处,16例(80.0%)DWI瘤壁呈等信号,壁内呈低信号。(3)脑脓肿形态规则,脓肿壁完整,出现"子母环征"、"环壁切迹征"、壁内液-液平面,脓肿包膜在T2 WI呈低信号"暗带",14例(93.3%)DWI壁及壁内呈高信号。结论 MRI可以显示颅内高级别胶质瘤、转移瘤、脑脓肿各自的特征性表现,并具有重要的鉴别诊断价值。

Objective To evaluate the value of MRI in differential diagnosis of circular enhanted brain le- sions. Methods Retrospective analysis of 50 cases of MR imaging of circular enhanced brain lesions, Which were proved by surgical operation or pathology and the clinical and imaging features. Results There were 15 of high - grade gliomas, 20 of brain metastasis and 15 of brain abscess were chosen in our study. The signs indicat- ing high - grade gliomas included wide range of lesions and with extension to the corpus coUosum in 13 cases（86. 6 % ）. rough outside wall and irregular in shape, multilocular lesion, multi mural nodule; 12 cases （80.0 % ）with DWI showed low signal and edge fuzziness. The signs indicating brain metastasis included The lesions were usu- ally limited and show circular shape, sharpness of border, small lesions, lesions located at the juncture of gray and white matter; 16 patients（80.0 % ） with DWI showed low signal in the inside of the lesion, and as middling sig- nal in the wall. The signs indicating abscess included conformation of rules and the wall is complete, circular wall notch sign, hype - intensity rim on T2WI and fluid - fluid level; 14 patients（93.3 % ）with DWI showed high sig- nal and ADC showed low signal. Conclusion The MRI can display the characteristic signs of brain metastasis, high- grade gliomas and brain abscess, which enjoys high value indifferential diagnosis.