脑膜瘤的磁共振成像和质子磁共振波谱

MR Imaging and Proton MR Spectroscopy of Meningiomas

探讨磁共振成像（ ＭＲＩ） 和质子磁共振波谱（１ Ｈ ＭＲＳ） 对脑膜瘤的诊断价值。材料和方法：３６４ 例行常规ＭＲＩ 检查， 其中１５ 例加做１ ＨＭＲＳ， 行肿瘤实质与健侧对应部位对照研究。结果： ＭＲＩ 平扫示： Ｔ１ ＷＩ５８ ．０ ％（２１１／３６４） 表现为等信号，３２ ．７ ％ （１１９／３４７） 为略低信号，９ ．３ ％ （３４／３６４） 为混合信号。Ｔ２ ＷＩ４０ ．１ ％ （１３９／３４７） 表现为等信号，４２ ．７ ％ （１４８／３４７） 表现为高信号，９ ．５ ％ （３３／３４７） 为略低信号，７ ．８ ％ （２７／３４７） 为混合信号。注射Ｇｄ － ＤＴＰＡ 后３３７ 例肿瘤实质部分均有不同程度的强化。６５ ．９ ％ （２２２／３３７） 出现“脑膜尾征”。５５ ．５ ％ （２０２／３６４）可见不同程度的水肿。１５ 例１ Ｈ ＭＲＳ 均表现为明显增高的胆碱（Ｃｈｏ） 峰，无氮乙酰门冬氨酸（ＮＡＡ） 峰，Ｃｈｏ／Ｃｒ（ 肌酸） 比值升高，ＮＡＡ／Ｃｒ 及ＮＡＡ／Ｃｈｏ 比值降低。４ 例出现乳酸峰（Ｌａｃ） 。结论：ＭＲＩ 平扫＋ 增强是诊断脑膜瘤的最主要方法，１ Ｈ ＭＲＳ 可作为很重要的补充。

Purpose:To evaluate the roles of MR imagimg and proton magnetic resonance spectroscopy (1H MRS) in the diagnosis of meningiomas. Materials and Methods:364 patients with meningiomas underwent conventional MRI.Among them,15cases had single voxel MR spectroscopy simultaneously both in the lesion's region and the contralateral side.Results:On pre-contrast MR images of 364 cases,T1WI showed 58.0%(211/364)isointensities,32.7%(119/364)faintly low intensities and 9.3%(34/364)mixed intensities.T2WI showed 40.1%(139/347)isointensities,42.7%(148/347)hyperintensities,9.5%(33/347)faintly low intensities and 7.8%(27/347)mixed intensities.After administration of Gd-DTPA,the solid part of the tumors exhibited various enhancement in all the 337 cases.“ Dural Tail sign 'was revealed in 222 of 337 cases (65.9%).Peritumoral edema was observed in 202 of 364 cases (54.9%).15 cases of MRS exhibited specific different spectral peaks including prominent choline-containing compounds (Cho), absent acetylaspartate(NAA)and decreased total creatine (Cr).4 cases showed abnormal lactate(Lac).The metabolic ratios showed significantly increased Cho/Cr,absent NAA/Cr and NAA/Cho.Conclusion:Conventional MRI is the most important dignostic means for meningiomas and MRS combined with MRI can improve diagnostic accuracy of meningiomas.