软脑膜异常强化的MRI表现及其诊断价值

Abnormal enhanced MRI findings of leptomeninges and their diagnostic value

目的:分析不同性质软脑膜病变的MRI表现,探讨其诊断价值。方法:回顾性分析38例软脑膜病变的增强MRI表现,其中软脑膜转移17例,感染性脑膜炎15例,脑梗塞5例,Sturge-Weber综合症1例,所有病例均经手术、临床和实验室检查证实。结果:软脑膜转移中结节样强化12例、弥漫对称性细线样强化12例,其中7例二者并存,未见粗线样或局灶性强化,除5例脑内伴转移瘤所致脑实质异常外,其余12例脑实质未见异常;感染性脑膜炎中线样强化14例,其中细线样及粗线样强化各7例,1例粗线样强化伴结节样强化,局限性、弥漫性强化分别为8例和7例,软脑膜邻近脑实质单纯性水肿者8例;脑梗塞中5例均表现为梗塞灶邻近软脑膜细线样强化,1例Sturge-Weber综合症表现为软脑膜粗线样强化,邻近脑实质萎缩。结论:MRI是检出软脑膜病变敏感和有效的方法,不同性质病变的软脑膜强化具有一定的特点,可为临床诊断、鉴别诊断和治疗提供线索。

Objective：To analyze enhanced MR imaging findings of different leptomeningcal disease and discuss enhanced-MRI value in their diagnosis. Methods： MR imaging manifestation of 38 patients with leptomeningeal disease were retrospectively reviewed. There were 17 cases with leptomeningeal metastasis, 15 cases with infectious meningitis,5 cases with cranial infarct, and one Sturge-Weber syn- drome. All were confirmed by operation, clinic and lahorotary examination. Patterns and distribution of leptomeningeal enhancement were analyzed. Results：The leptomeningeal enhancement in 12 of 17 patients with metastasis appeared as nodular pattern, while 12 cases appeared as diffused fine linear pattern. There were 7 cases with the two enhancement patterns, and 5 cases complicated with cranial parenchyma involvement. Among the 15 cases with infectious meningitis, there were 14 cases wtih linear enhancement, including 7 cases with fine linear enhancement and 7 cases with thick linear enhancement respectively. Eight cases with focal enhancement and 7 cases with diffused enhancement were observed. Adjacent parenchyma edema occurred in 8 cases. All 5 cases with cranial infarct appeared as fine linear leptomeningeal enhancement adjacent to lesions. The one case with Sturge-Weber syndrome manifested as thick linear enhancement with parenchyma atrophy. Conclusion： MRI is sensitive and effective approach to detect leptomeningeal diseases, leptomeningeal enhancement of different causes has relative characteristic. It＇s helpful for diagnosis, differentiation and management.