Objective:To study the changes and imaging features of arachnoid granulation (AG) in patients with cerebral venous sinus thrombosis (CVST).Methods:The clinical and imaging data of 35 patients with idiopathic CVST confirmed by MR imaging combined with CE-MRV or DSA in our hospital from January 2013 to December 2018, and 35 healthy controls collected at the physical examination center at the same time period were detected. The sizes and numbers of AG were compared between the two groups, and the MR imaging features of CVST and AG in patients with CVST at different courses were compared.Results:(1) In 35 patients with CVST, AG was found in 14 patients, and the average diameter was (5.19±2.40) mm, ranged from 1.83-11.77 mm; in the control group, AG was found in 23 patients, and the average diameter was (4.45±2.03) mm, ranged from 1.45-9.87 mm; no statistical difference was noted in diameter between the two groups ( t=2.121, P=0.221), and the number of AG showed statistical difference between the two groups (χ 2=4.644, P=0.031). (2) In 8 patients with CVST at acute phase, CVST showed hypointense on T2WI and FLAIR; in 20 patients with CVST at subacute phase, CVST showed hyperintense on T2WI and FLAIR; in 7 patients with CVST at chronic phase, CVST showed hyperintense on T2WI and FLAIR. At any stage of venous sinus thrombosis, AG showed high signal on T2WI and low signal on FLAIR. Conclusion:AG detection rate in CVST patients is lower than that in normal controls; MR imaging T2WI and FLAIR sequences could effectively distinguish CVST with AG.

Objective:To explore the diagnostic values of MRI T2WI and 3D contrast enhanced magnetic resonance venography (3D CE-MRV) in transverse sinus arachnoid granulations (AGs).Methods:Clinical data were obtained from 811 patients who were subjected to non-contrast MR imaging and 3D CE-MRV between January 2016 and April 2019 in our hospital. And the number of patients whose transverse sinus AGs could be shown by T2WI and MRV, the number, size, and shape of AGs, and the number of AGs-related veins were recorded.Results:MRI T2WI showed 242 AGs in 184 patients (22.7%), and 3D CE-MRV showed 138 AGs in 119 patients (14.7%); MRI T2WI had a significantly higher percentage in showing AGs patients as compared with 3D CE-MRV ( P<0.05). Two hundred and forty-two AGs showed by MRI T2WI were divided into 3D CE-MRV observation group ( n=138) and 3D CE-MRV non-observation group ( n=104); the diameter of AGs in the 3D CE-MRV non-observation group ([5.30±2.10] mm) was significantly smaller than that in the 3D CE-MRV observation group ([6.14±2.03] mm, P<0.05). MR T2WI showed that 231 AGs were like circles or ellipses and 11 AGs were like fractal; while 3D CE-MRV showed that 138 AGs were like circles or ellipses and 0 AG were like fractal. MRI T2WI showed that 289 veins were closely related to AGs, and 3D CE-MRV showed that 97 veins were closely related to AGs. MRI T2WI could demonstrate significantly higher proportion of non-labbe veins which were closely related to AGs than 3D CE-MRV ( P<0.05). Conclusion:As compared with 3D CE-MRV, T2WI can find larger number of AGs in the transverse sinus, and better display the shape of AGs and the vein adjacent to them.