脑静脉及静脉窦血栓的MR征象分析

MR Imaging Features of Cerebral Venous and Sinus Thrombosis

目的总结脑静脉及静脉窦血栓形成(CVST)的MRI及MRV成像特点,提高对其影像诊断水平。资料与方法回顾分析39例经DSA或临床随访证实的CVST患者的临床及影像资料。结果所有病例均行MRI平扫,19例行增强扫描,26例行MR静脉成像(MRV)。MRI平扫表现为静脉窦流空信号消失(38/39),血栓信号随病程长短而不同,急性期(11/38),血栓于T2WI多呈低信号(7/11),T1WI呈等信号(6/11)或略高信号(5/11);亚急性期(17/38),T2WI多呈高信号(12/17)、T1WI也多呈高信号(14/17);慢性期(10/38),T2WI多呈高信号(8/10),T1WI多呈等信号(6/10)。增强扫描急性及亚急性期血栓均表现为受累静脉窦充盈缺损,慢性期多表现为血栓明显不均匀强化(6/7),静脉窦壁增厚毛糙。67%(26/39)病例出现闭塞静脉窦相应引流区域脑组织肿胀甚至出血,增强扫描肿胀区可出现异常强化(8/17),脑膜亦可强化(6/17);同时在闭塞静脉窦引流区可见多发强化血管信号(12/17)。23例26人次MRV均可显示闭塞静脉窦血流信号缺失,其中2例治疗后静脉窦再通显示为不规则血流信号形成。结论 MRI结合MRV是CVST首选的无创检查方法,有助于CVST的早期诊断及排除诊断。

Objective To valuate the appearance of cerebral venous thrombus（CVT） and to improve the imaging diagnosis.Materials and Methods Imaging findings and clinical presentations of 39 patients with CVT confirmed by DSA or clinical follow-up were evaluated retrospectively.Results ALL the patients underwent unenhanced MR scanning,19 of them underwent enhanced scanning and 26 patients underwent MRV scanning.The absence of flow void was a primary finding of sinus thrombosis on MR images（38/39）.The signal intensity of venous thrombi on T1-and T2-weighted varied according to the interval between the onset of thrombus formation and the time of imaging.In the acute stage of thrombus formation（11/38）,the signal is predominantly hypointense on T2-weighted images（7/11） and isointense（6/11） or hyperintense（5/11） on T1-weighted images.In the subacute stage of thrombus formation（17/38）,the signal is predominantly hyperintense on both T1-weighted images（14/17） and T2-weighted images（12/17）.The signal in the chronic thrombus（10/38） is typically hyperintense on T2-weighted images（8/10） and isointense on T1-weighted images（6/10）.Filling defect of venous sinus was found on enhanced MRI in cases of acute and subacute sinus thrombosis.However,marked heterogeneous enhancement with thick and rough sinus wall were observed in cases of chronic sinus thrombosis（6/7）.Focal brain edema or hemorrhage have been identified in 67% of patients（26/39）.Parenchymal enhancement（8/17） and mater enhancemen（6/17） were observed and cortical venous enhancement also was visible after the administration of contrast（12/17）.Filling defect was observed in the segment of sinus thrombosis on MRV of 23 patients.The irregular blood flow signal were noted for incomplete recanalization of the sinus in 2 patients.Conclusion MRI combined MRV is a primary noninvasive methods for early diagnosis of venous sinus thrombosis.