脑静脉窦血栓的常规MRI及MR扩散加权成像研究

The conventional MRI and diffusion-weighted imaging in cerebral venous sinus thrombosis

目的:探讨常规MRI、扩散加权成像(DWI)对脑静脉窦血栓(CVST)的诊断价值,评价栓塞静脉窦的扩散信号表现预测治疗后对应的静脉窦再通的可能性。方法:回顾性分析32例CVST的常规MRI、MR静脉成像和DWI表现。以首次DWI检查栓塞的静脉窦表现分高信号组、等或低信号组,随访28例76支栓塞的静脉窦再通情况,两组间的完全再通率比较采用χ2检验。结果:常规MRI和MR静脉成像发现32例CVST。5例单支静脉窦受累,8例2支静脉窦受累,13例3支静脉窦受累,4例4支静脉窦受累,2例5支静脉窦受累。86支CVST中,61.6%在T1WI呈高信号,47.7%在T2WI呈高信号,46.5%在T2FLAIR呈高信号,32.6%在DWI呈高信号。首次DWI检查25支栓塞的静脉窦呈高信号者,随访检查7支静脉窦完全再通,10支静脉窦部分再通,8支静脉窦仍见阻塞。首次DWI检查51支栓塞的静脉窦呈等或低信号者,随访检查36支静脉窦完全再通,9支静脉窦部分再通,6支静脉窦仍见阻塞。DWI检查栓塞的静脉窦呈高信号者较无高信号者,随访复查栓塞的静脉窦完全再通率减低,两者之间的差异有统计学意义(χ2=12.46,P<0.05)。结论:CVST患者已行常规MRI检查时,DWI检查不具有补充的诊断价值。DWI检查CVST呈高信号者,提示栓塞的静脉窦再通机会减低。

Objective： To investigate value of conventional MRI, diffusion-weighted imaging （DWI） in diagnosing cerebral venous sinus thrombosis （CVST）, to evaluate diffusion signal intensity in occluded venous sinuses and predict the chances of vessel recanalization at the corresponding site. Methods： The conventional MRI, MR venography and DWI findings were analyzed retrospectively in 32 patients with CVST. The patients were divided into 2 groups according to the signal of the throm- bosed sinus on the first DWI, that is a group with hyperintense signal and isointense/hypointense signal. Complete recanaliza- tion between groups were compared by x2 test. Results： Thirty-two patients with CVST were observed on MRI combined with MR venography. One venous sinus was involved in 5 patients, 2 in 8 patients, 3 in 13 patients, 4 in 4 patients, and 5 in 2 patients. Among the 86 sites of CVST, thrombosis demonstrated hyperintense signal on T1WI in 61.6% of sites, on T2WI in 47.7%, on T2 FLAIR in 46.5%, on DWI in 32.6%. Twenty-five thrombosed sinuses demonstrated hyperintense signal on the first DWI, complete recanalization was found in 7 sinuses, partial in 10, and occluded in 8 at follow-up examinations. Fifty- one thrombosed sinuses demonstrated isointense or hypointense signal on the first DWI, complete recanalization was found in 36 sinuses, partial in 9, and occluded in 6 by follow-up examinations. Chances of eomplete reeanalization was lower in the presence than in the absence of hyperintense signal in thrombosed sinuses on the first DWI, there was statistically significant differenee （x2=12.46, P〈0.05）. Conclusion： DWI examination is of no additional diagnostic value when conventional MRI are al- ready obtained for patients with CVST, The hyperintense signal in thrombosed sinus on DWI suggests low rate of vessel recanalization at follow-up examination.