脑静脉窦蛛网膜颗粒的CT和MRI诊断

目的 探讨脑静脉窦内蛛网膜颗粒的CT和MRI影像特点。方法 8例脑静脉窦内蛛网膜颗粒患者行MRI检查，其中7例行CT扫描，对影像进行回顾性分析，总结其特征性征象。结果 8例患者中，脑静脉窦内蛛网膜颗粒共有9个，其中6个位于横窦，3个位于上矢状窦。病灶在CT影像中均表现为低密度影，其中3个有钙化灶。9个Tl加权像为低信号，1、2加权像为高信号，7个液体衰减反转恢复序列上为低信号；4个增强后可见轻度或中度强化，以及充盈缺损；4个MR静脉造影影像呈附壁状充盈缺损征象。结论 CT和MRl影像是诊断脑静脉窦内蛛网膜颗粒的有效方法，特别是MRl影像能显示其特征性信号改变及与静脉窦的关系，对诊断更有意义。

The value of CT and MRI in the detection of cerebral arachnoid granulations

Objective To evaluate the diagnostic utility of CT and MRI in the detection of arachnoid granulations located in cerebral venous sinuses. Methods MRI were applied in 8 patients for detection of araehnoid granulations, 7 of them also underwent CT scan. All of the images were analyzed retrospectively. Results There were 9 arachnoid granulations found in the 8 patients. 6 of them were located in transverse sinus while 3 in superior sagittal sinus. 7 araehnoid granulations were manifested low density in CT, 3 of them with calcification. All of 9 arachnoid granulations showed low signal in T1WI and high signal in T2WI of MRI. 7 of them showed low signal in Flair sequence, 4 showed mild or moderate enhancement and filling defeet sign. Filling defect was seen in cerebral MRV in 4 eases. Conclusion Both CT and MRI are reliable methods to verify araehnoid granulations, but MRI is more useful in identifying their relation with venous siNuses.