淋巴瘤脑脊膜侵犯的MRI表现

Findings in MRI when lymphoma invades cerebro-spinal meninges

目的探讨淋巴瘤脑脊膜侵犯的途径和MRI表现特征。方法回顾性分析我院1996年8月至2004年12月收治经病理确诊的12例淋巴瘤脑脊膜侵犯患者的MRI资料。结果全部病例经脑或(和)脊椎MRI平扫加Gd-DTPA增强扫描。12例均为非霍奇金淋巴瘤,2例为脑原发性淋巴瘤,10例为继发性脑和脊柱淋巴瘤。7例经手术病理诊断,5例经活检病理确诊。单纯脑部受侵犯5例,单纯脊柱受侵犯6例,脑和脊柱均受累1例。单纯脑膜受侵2例,脑膜和脑组织同时受累4例,表现为硬脑膜-蛛网膜型4例,脑室内软脑膜及室管膜下受侵2例。7例硬脊膜病灶表现为斑片状、条状,病灶上下端可见杯口征或脊膜尾征,T1WI脑脊膜病灶均呈稍低信号或等信号,T2WI均呈稍高信号;增强后脑脊膜病灶均呈中-高度强化,T1WI脂肪抑制序列病灶显示更清楚。结论MRI检查能清楚显示淋巴瘤脑脊膜受侵病灶的部位和范围。

Objective To probe routes via which lymphoma invades cerebro-spinal meninges and corresponding findings in MRI. Methods 12 cases whose cerebro-spinal meninges were invaded by lymphoma （pathologically proven） were retrospectively reviewed. All cases had undergone plain scan and Gd-DTPA enhanced scan on brain and/or spine using MRI. Results All 12 cases were non-Hodgkin lymphoma. 2 cases were primary cerebral lymphoma and the remaining 10 were secondary. 7 cases were surgically and pathologically proven and 5 were proven by biopsy. 5 cases had lesions exclusively in brain, 6 cases exclusively in spine, and 1 case had both brain and spin involved. 3 cases had lesions exclusively in meninges, 4 cases had both meninges and brain tissue involved. 4 cases had cerebral dura mater and arachnoid involved, 2 cases had cerebral pia mater inside the ventricles and sub-ependyma involved. 7 cases whose lesions in spinal dura mater manifested as patch or cord-shape lesions showing crateriform depression or spinal meningeal tail sign. The lesions in cerebro-spinal meninges showed slightly low or isointensity on T1WI, slightly high signal intensity on T2WI. The lesions had been mid-high enhanced and became more clearly on fat-suppressed sequence on T1WI after enhancement. Conclusion MRI is able to clearly show location and scope of lesions that are caused by invasion of lymphome into cerebro-spinal meninges.