脑静脉血管瘤的MRI及MRA

MRI and MRA Features of Cerebral Venous Angiomas

目的：探讨颅内静脉血管瘤的ＭＲＩ和ＭＲＡ影像学表现及诊断和鉴别诊断。材料和方法：应用ＳｉｅｍｅｎｓＭｅｇｎｅｔｉｏｎＶｉｓｉｏｎ１．５Ｔ超导系统对诊断静脉血管瘤（ＶＡ）２０例进行分析。ＭＲＩ扫描用ＳＥＴ１和ＴｕｒｂｏＳＥＴ２加权序列。ＭＲＡ采用ｔｏｆ－ｔｉ３Ｄ－ｍｕｌｔｉ－ｓｌａｂ－ｔｒａ－ｔｕｎ序列。１６例作增强Ｔ１加权及ＭＲＡ检查。血管重建采用ＭＩＰ技术。有１１例曾行ＣＴ检查，１例行手术治疗。结果：所有病例均由ＭＲ检查作出首诊。Ｔ１加权１８例显示扩张引流静脉呈点条状低信号影，有２例未显示，经增强后显示，并有部分髓静脉显示。Ｔ２加权引流静脉多呈高信号，个别呈低信号。较大的ＶＡ亦可显示髓质静脉。ＭＲＡ１５例显示异常血管，典型的表现为脑实质内见为数不等的髓质静脉呈伞状汇入一根异常扩张的引流静脉，整个形态似“水母头”。１例ＭＲＡ未显示病灶。结论：ＭＲ是诊断ＶＡ最好的影像方法，ＭＲＡ有助于确诊本病。

Purpose:To analyse the imaging characteristics of cerebral venous angiomas(VA) and to evaluate MRI and MRA in the diagnosis and differential diagnosis of this vascular malformation.Materials and Methods:20 patients of VA were studied by Siemens Megnetion Vision 1.5T Super Conductive MR system.MRI was performed with SET1 and Turbo SET2 weighted sequences and MR angiography with“tof-ti3D-multi-slab-tra-tun' sequences and MIP postprocessing technique.T1 weighted with enhancement scan and MR angiography were done in 16 patients.CT was also performed in 11 patients and proved by operation in 1 patient.Results:All patients were first diagnosed by MRI.The dilated draining veins can be shown in 18 cases as stripes of hypointensities(flow-void-sign) on T1WI,while hyperintensities on T2WI,some can also be shown as the flow empty signals.2 patients did not be revealed on T1WI,but all were displayed after being injected with Gd-DTPA. The fairly large VA defined medulla veins on T2WI plain MRI.Most of them were shown on contrast enhanced MRI.15 patients of VA showed vascular malformation on MRA and characteristically appeard as varies in number of medulla veins converging into an abnormal dilated draining vein in the brain parenchyma as a fimbria.The whole shape was like a “Caput Meduse'.MRA failed to demonstrate the focus in 1 patient.Conclusion:MRI is the best imaging diagnostic method of VA.Contrast enhancement MRI can definitely increase the detection rate of VA.MRA is helpful in definite diagnosis of VA.