脑静脉畸形的MRI诊断(附8例分析)

目的:探讨脑静脉畸形的MRI表现,评价各成像序列的诊断价值。材料与方法:搜集8例脑静脉畸形病例,均行常规MRI平扫及三维多个重叠薄层采集(3D-MOTSA)MRA检查。6例行Gd-DTPA增强T1WI扫描,其中3例行3D-MOTSA增强MRA检查。结果:小脑4例,额叶、顶叶、枕叶共4例。5例MRI平扫引流静脉为长T1、短T2流空信号,3例呈长T1低信号、长T2高信号。扩张的髓静脉为网状及条状长T1低信号、长T2高信号,增强呈“海蛇头”样改变,即多条髓静脉呈辐射状汇入粗大的引流静脉。3D-MOTSA MRA检查显示部分引流静脉,髓静脉显示较少。3例3D-MOTSA增强MRA检查引流静脉全程显示,髓静脉显示数目多。结论:MRI能明确诊断脑静脉畸形的合并症,弥补脑血管造影的不足,3D-MOTSA增强MRA检查可取代脑血管造影。

MRI diagnosis of cerebral venous malformation(report of 8 cases)

Objective: To study MRI features of cerebral venous malformation(CVM), and assess the value of each imaging sequence. Methods: MRI and three-dimensional multiple overlapped thin slab acquisition(3D-MOTSA) MR angiography(MRA) were performed in 8 cases with CVM. Six patients were imaged by MR scanner with Gd-DTPA enhanced T1WI, and 3 of them underwent additional 3D-MOTSA CE MRA. Results: In 4 cases the lesions were located in cerebellum and 4 cases in frontal lobe, parietal lobe or occipital lobe. In 5 cases, MRI showed draining veins which were hypointense on T1WI and T2WI, hypointense on T1WI and in 3 cases showed hyperintense on T2WI, while medullary veins showed hypointense on T1WI and hyperintense on T2WI. After enhancement, numerous radiating medullary veins gathered together into one or two larger draining veins and flowed into superficial or deeper veins, demonstrating the so-called "Caput Medussa" appearance. 3D-MOTSA MRA showed some draining veins, but a few medullary veins. 3D-MOTSA CE MRA could show the whole length of the draining veins in 3 cases, the number of medullary veins were numerous. Conclusion: MRI could diagnose the complications of CVM accurately and make up for the deficiency of cerebral angiography. 3D-MOTSA CE MRA could replace cerebral angiography.