脑胶质瘤柔脑膜转移的MRI诊断

Magnetic Resonance Imaging in the Evaluation of Leptomeningeal Metastasis of Gliomas

目的结合文献探讨胶质瘤柔脑膜转移的MR影像学特征,为临床提供早期诊断和治疗依据。方法搜集21例诊断脑胶质瘤柔脑膜转移的病人MR扫描资料,扫描选用常规自旋回波脉冲序列,8例加扫液体衰减反转恢复脉冲序列,全部病例均行增强扫描。结果⑴平扫18例表现为不同范围脑池、脑沟变形结构模糊,脑回肿胀;6例表现为脑室壁不均匀增厚;7例蛛网膜下腔发现结节11个,部分病例上述表现合并存在,其中8例另选用液体衰减反转恢复脉冲序列扫描,转移病灶轮廓显示较常规SE序列清晰,信号略高于TSE-T2加权像,瘤体边缘与周围水肿难于分辨。⑵增强扫描后脑胶质瘤体均显著增强,柔脑膜转移显示呈不同强化特征,5例“尾征,”10例“线征,”3例“条索征”及7例“环征或结节征”,少部分病例合并两种征象存在。结论加深对胶质瘤柔脑膜转移的MR影像特征的认识,选择适当的MR成像技术,提高脑膜病变的早期检出率,对临床选择治疗方案具有十分重要的意义。

Objective To evaluate the characteristics of leptomeningeal metastasis of gliomas on magnetic resonance（MR） imaging and to provide evidence for clinical early diagnosis and treatment. Methods Twenty-one cases of intracranial gliomas with leptomeningeal metastases were scanned with conventional spin echo （SE） and fast spin echo （TSE）, 8 cases with fluid attenuated inversion recovery （FLAIR）, and all of cases were operated with enhancement. Results （1） With MR plain scan, 18 cases revealed vary range of distortion and illegibility structure of cerebral cistern and sulcus, and 6 cases revealed the asymmetrical enhancement of the wall of ventricle. Eleven meningeal neoplasms nodes were found in subarachnoid space in 7 cases, and some of the appearances could be seen in several cases. Eight eases of them were added with FLAIR, and the neoplasms nodes were showed more clearly and higher signal than TSE-T2W imaging. （2） With MR enhancement, all cases with encephalic gliomas showed obvious enhancement with vary features of the enhancement of leptomeningeal metastasis, including tail sign （5/21）, line sign （10/21）, strip sign （3/21）, node sign （7/21） and a few of cases included two signs. Conclusion It was very important for clinician to improve the cognition of MR imaging characteristics of leptomeningeal metastases of glioma, and to choose the proper MR imaging scan technique to increase the detection rate of early meningeal diseases.