颅内原发恶性肿瘤柔脑膜转移的MRI诊断

MR Imaging in the Evaluation of Leptomeningeal Metastasis of the Primary Encephalic Neoplasm

目的:探讨颅内原发恶性肿瘤柔脑膜转移的MR影像学特征,为临床提供早期诊断和治疗依据。方法:搜集33例诊断颅内原发恶性肿瘤柔脑膜转移患者的MR扫描资料,扫描选用常规自旋回波脉冲序列,10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:平扫表现为不同范围脑池、脑沟和/或脑室变形、移位,结构模糊,其中28例伴有明显脑回肿胀,合并脑室壁不均匀增厚8例;合并蛛网膜下腔肿瘤结节9例,共发现结节17个,合并脑积水10例,部分病例上述表现合并存在,其中10例另选用液体衰减反转恢复脉冲序列扫描后,转移病灶轮廓显示较常规SE序列清晰,信号略高于TSET2WI,瘤体边缘与周围水肿难于分辨。增强扫描后脑内瘤体均明显增强,柔脑膜转移显示呈不同强化特征,8例尾征,14例线征,6例条索征及9例环征或结节征,少部分病例合并两种征象存在。结论:加深对颅内原发恶性肿瘤柔脑膜转移的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 the primary encephalic neoplasm on MR imaging and to provide evidence for clinical early diagnosis and treatment. Methods：33 cases of the primary intracranial neoplasm with leptomengeal metastases were scanned with conventional SE and TSE, 10 cases with FLAIR, all cases were operated with enhancement. Results： MR plain scan： all cases revealed varying range of distortion and illegibility structure of cerebral cistern and sulcus,and/or revealed distortion of the ventricle, 28 cases showed obvious gyrus tumefaction,8 of them could be seen the asymmetrical thickening of the wall of the ventricle,17 meningeal nodes were found in subarachnoid space in 9 cases and 10 of them showed hydrocephalus,some of them could be seen those two appearances. 10 of them were added with FLAIR,where nodes were showed more clearly and higher singal intensity than TSE and T2W imaging,the edge of neoplasm could not be distinguished from edema. MR enhancement：All the encephalic neoplasm showed obvious enhancement with varying features of the enhancement of leptomeningeal metastasis,including tail sign （8/33）,line sign（14/33） .strip sign （6/33）,node sign （9/33）,few of the cases including two signs. Conclusion： Improving the cognition of MR imaging characteristics of leptomeningeal metastases of the primary encephalic neoplasm for clinician to choose proper MR imaging scan technique and to increase the detection rate of early meningeal diseases,which is very significant for clinical therapy.