三维增强磁共振静脉成像评价颅内静脉系统

目的:比较三维增强FLASH序列和2D TOF序列MR静脉成像(MRV)对颅内静脉系统的诊断价值.方法:本组11例中健康志愿者6例(正常组),脑静脉窦血栓形成患者5例(病变组),均同时行3D增强FLASH和2D TOF序列MRV扫描,病变组5例患者同时行DSA检查.将脑内主要静脉(14支)的显示情况分为3级:满意显示,一般显示和未显示.比较两种扫描方法对脑内静脉和静脉血栓的显示情况.结果:正常组中三维增强FLASH和2D TOF序列对所观察的14支脑静脉的满意显示率、一般显示率和未显示率分别为88.10%,5.95%,5.95%和30.95%,53.57%,15.48%.三维增强FLASH未显示结构主要为下矢状窦.病变组5例中DSA共发现12处血管病变,三维增强FLASH显示优于2D TOF 10处,两者相仿2处.结论:三维增强FLASH对脑静脉系统的显示优于2D TOF序列,可以提供高质量的脑内静脉结构的图像,对诊断脑静脉内血栓形成有重要临床价值.

Evaluation for Intracranial Venous System with 3-Dimensional Contrast Enhancng MR Venography

Objective:To comparatively study the clinical diagnostic value of the three-dimensional gadolinium-enhancing fast low angle shot sequance(3DE FLASH) with that of the two-dimensional time of flight(2D TOF) in the diagnosis of intracranial venous system diseases.Methods:3DE FLASH,2D TOF and cranial DSA were all performed the same time intervals in 11 cases(including 5 healthy volunteers without any intracranial diseases,designated as group of volunteers,and 5 patients with intracranial venous thrombosis,designated as group of patients).The MR demonstration of intracranial veins with these 2 angiographic techniques was correlatively compared.On MR venograms,the demonstration of 14 major intracranial veins was defined as 3 grades:satisfactorily demonstrated,demonstrated and poorly demonstrated.Two readers were asked to compare and evaluate independently the demonstration of the 14 major intracranial veins and thrombosed veins on the MR venograms respectively scanned with the 2 different techniques.Results:In group of volunteers,the demonstration rates of the 14 major intracranial veins on the venograms scanned with 3DE FLASH and 2D TOF techniques were shown as:satisfactorily demonstrated rates 88.10% and 30.95%,demonstrated rates 5.95% and 53.57%,as well as poorly demonstrated rate 5.95% and 15.48% respectively.The venous structure that was poorly demonstrated on 3DE FLASH images was primarily the inferior sagittal sinus.Using the DSA demonstration of the major and thrombosed veins as a standard,12 venous lesions were found with DSA in the 5 cases of group of patients.10 of the 12 venous lesions were better demonstrated on 3DE FLASH scans than on 2D TOF images,however,their demonstration of the remaining 2 lesions was very much similar.Conclusion:3DE FLASH was better than 2D TOF in displaying intracranial venous system.The former provided high quality images of intracranial venous structures and was very valuable for the detection and diagnosis of intracranial venous and sinus thrombosis.