Microanatomy And Neuroimaging Of The Orifice Of Cerebral Bridging Veins Into The Suprior Sagittal Sinus

Objectives The aim of this study was to perform an microanatomy and neuroimaging with computed tomographic venography (CTV) and contrast enhancement magnetic resonance (CE-MR) of the orifice of cerebral bridging veins (BVs) into the suprior sagittal sinus (SSS), in order to provide a morphologic basis for the mechanism of cerebral venous diseases and the neuroimaging diagnosis.Methods Thirty cadaeric head sepcimens (sixty sides) were used in microanatomy, including twenty-three male and seven female, aged 40±11. The number, the location, the types and the line feed of the orifice were recorded after poured into blue galatin or blue latex. Forty patients without cerebral venous diseases or injury were choosed, including twenty-four male and sixteen female, aged 46±13. The CTV and CE-MR examination in twenty patients were performed separately with the same content as the microanatomy.Results 1. The results of the microanatomy.①The number of the orifice A total of 367 outer orifices and 375 inner orifices were found. The outer orifice was the junction outside of the SSS between BVs and dural mater. The inner orifice was the sinusal entrance inside of the SSS. There were eight cases which two inner orifices drained one BV into the SSS with one outer orifice. The orifice mainly located in the anterior segment and the posterior segment of the SSS, while the number of the outer orifices were 128 and 239 separately.②T he type of the orifice There were two type orifices. Some outer orifices directly drained into the SSS, and the others drained into the SSS indirctly by the meningeal veins or parasagittal sinuses. The menigeal veins were the especial veins in the dural mater para by the side of the SSS or the cerebral falx. The parasagittal sinuses were the small lacouna in the flank wall of the SSS.③The line feed of the orifice A total of 21 outer orifices drained into the anterior segment of the SSS indirctly, in which 24% (5/21) outer orifices changed the dirction of the BVs from against the direction of blood flow in the SSS to along or at a right angle. A total of 89 outer orifices drained into the posterior segment of the SSS indirctly, in which 85% (76/89) outer orifices changed the dirction of the BVs from against the direction of blood flow in the SSS to along or at a right angle.④The location of the inner orifice There were 128 inner orifice in the anterior segment of the SSS, including 88% in the flank angle 7% in the flank wall and 5% in the following angle. There were 247 inner orifice in the posterior segment of the SSS, including 29% in the flank angle 43% in the flank wall and 28% in the following angle. The number of the inner orifice in the flank wall and the following angle in the posterior segment of the SSS is much more than the anterior segment. The number of the inner orifice in the flank angle of the SSS is less than the anterior segmengt. 2. The results of the neuroimaging.①The number of the orifice CTV was a better method to observe the whole orifice. A total of 186 outer orifices and 190 inner orifices were found. There were four cases which two inner orifices drained one BV into the SSS with one outer orifice. The number of the orifice located in the anterior segment and the posterior segment of the SSS were 64 and 122 separately. Compared with the results of the microanatomy, only 76% of the orifices were found by CTV.②The type of the orifice The orifices drained into the SSS indirectly by the meningeal veins in the dural mater and the parasagittal sinus by the side of the SSS were observed by the CTV. The orifices drained into the SSS indirectly by the parasagittal sinuses were the small lacouna in the flank wall of SSS were observed by the CE-MR. The orifices drained into the SSS indirectly by the meningeal veins in the cerebral falx were observed neither CTV nor the CE-MR.③The line feed of the orifice The orifice can exposed clearly in the CTV.③The line feed of the orifice The line feed of the orifice were displayed clearly by CTV. A total of 11 outer orifices drained into the anterior segment of the SSS indirctly, in which 36% (4/11) outer orifices changed the dirction of the BVs from against the direction of blood flow in the SSS to along or at a right angle. A total of 36 outer orifices drained into the posterior segment of the SSS indirctly, in which 83% (30/36) outer orifices changed the dirction of the BVs from against the direction of blood flow in the SSS to along or at a right angle. There were no statistical diffrence between the results of the microanatomy and CTV.⑤The location of the inner orifice In the coronal section, the relation of the orifice and the SSS exposed clearly in the CE-MR image. Compared with the results of the microanatomy, the number of the orifice in the CE-MR reduced apparently and the inner orifice in the following angle coulad not be observed. The rate of the inner orifice in the flank angle is no difference from the inner orifice in the flank wall in statistics.Conclusion①This study reveals the complexity of the orifice and one outer orifice .can relate with two inner orifice.②The orifice frequently changed the direction of the BVs and played an important part for reducing the cerebral venous system thrombosis.③The location, the types and the line feed and other morphology of the orifice could be exposed clearly by CTV and CE-MR.