MRI对恶性脑膜瘤的诊断价值

The value of MRI in diagnosis of malignant meningioma

目的探讨磁共振成像（MRI）住恶性脑膜瘤诊断中价值。方法回顾性分析19例恶性脑膜瘤患者的MRI检查和其他临床资料，重点观察肿瘤的部位、形态、大小、MRI信号特点、瘤周水肿情况及周围组织浸润情况。结果肿瘤多发于大脑凸面及矢状窦旁，直径为1．6～11．8cm，肿瘤呈分叶状7例，不规则形8例，类圆形4例；6例边缘清楚，13例边缘不清楚，对周围组织不同程度侵犯；15例肿瘤周围见不同程度水肿；平扫T1WI呈低信号8例．低、等混杂信号10例，高信号1例，T2WI呈低信号2例，等信号4例，高、等信号13例。6例信号均匀，13例信号不均匀，内见不规则坏死或囊变区；增强扫描4例呈均匀强化，15例不均匀强化。13例肿瘤周围见短粗不规则的“脑膜尾征”。结论恶性脑膜瘤MRI表现具有一定特征性，MRI检查在恶性脑膜瘤的定性、定位诊断中具有重要价值。

Objective To investigate the value of magnetic resonance imaging （MRI） in the diagnosis of malignant meningioma. Methods Analyzed MRI examination and other clinical data of 19 patients with malignant meningioma retrospectively, and the tumor location, size, shape, signal characteristics of MRI, peritumoral edema and the surrounding tissue infiltration were observed. Results Meningiomas were mainly located at the convexity of brain and sagittal sinus, diameters were 1.6-11.8 cm, tumors showed lobulated shape in 7 cases, irregular shape were showed in 8 cases, oval in 4 cases; The boder was clear in 6 cases, ill defined in 13 cases, and invaded the surrounding tissue in varying degrees; Edema in varying degrees were seen in 15 cases; The tumors were low hypointense on T1 weighted （T1WI） images in 8 cases, low, equal mixed signal in10 cases, high signal in 1 case, The tumors were hypointense on T2 weighted （T2WI） images in 2 cases, equisignal in 4 cases, high signal and equisignal in 13 cases, homogeneous signal in 6 cases, inhomogeneous signal in 13 cases, irregular necrosis or cystic areas were seen inside; Homogeneous enhancement were seen in 4 cases, heterogeneous enhanced in 15 cases. Short and thick irregular ＂dural tail sign＂ were showed in tumours surrounding in 13 cases. Conclusion Malignant meningioma has characteristics in MRI, MRI examination has important value in the qualitative diagnosis, and localization diagnosis in malignant meningiomas.