The Study Of Magnetic Resonance Venography Of The Superficial Cerebrovenous System And Its Implication

Objectives To study the related microneurosurgical planning and morphological basis for the genesis of cerebral venous diseases and provide timely angiographic diagnosis for cerebral venous diseases accurately,the difference of CE-MRV and TOF-MRV of the superficial cerebrovenous system were analyzed.Methods①This study involved 16 patients without cerebral venous diseases and damaged veins.Images of the superficial cerebrovenous system were obtained with TOF-MRV and CE-MRV.②To investigate the imaging appearance,the superficial cerebrovenous system was divided into two parts:the cerebral bridging veins and the region of the torcular Herophili.The cerebral bridging veins were divided into three groups:superior saggital group,supratentorial group and sphenoidal group.The region of the torcular Herophili is the anastomosis of superior saggital sinus,strait sinus,sinus and transverse sinus.③To compare the two ways of MRV and find out the difference between them.Results 1.Superior sagittal group①Anterior to the coronal suture was a segment of superior sagital sinus(SSS) void of bridging vein draining into.The length was 27.00±11.36mm and 27.00±11.09mm on the venogram obtained by CE-MRV and TOF-MRV respectively.②Most of the bridging veins entered SSS from the posterior to the anterior at acute angle,the bridging veins on the venograms obtained by CE-MRV and TOF-MRV were 60.6%and 52.9%respectively.2.Supratentorial group①Based on the location of entering point,the bridging veins were divided into two subgroups: transverse sinus group and petrosal group.②The configuration of the location of termination yields three types:single vein type,separated type,candelabra type.③MRV dissection showed the bridging veins drained the lateral and basal surface of the temporal and occipital lobe.④The bridging veins entering transverse sinus were found both in 90%venograms obtained by CE-MRV and TOF-MRV.The bridging veins entering petrosal group were found in 40%and 47%venograms obtained by CE-MRV and TOF-MRV respectively.⑤The sensitivity of depicting Labbe veins(LV) on the venograms obtained by CE-MRV and TOF-MRV were 78%and 81%respectively. More than half of vein of Labbe entering points(53.6%and 50%) were transverse group. 3 Sphenoidal group①The superficial middle cerebral veins(SMCV) were classified into four types according to the number of stems draining into the dural sinus: hypoplastic,single stem,double stems and three stems.The percent of the hypoplastic observed in CE-MRV and TOF-MRV was 12.5%and 28.1%respectively.②Both of the MRV reavealed the SMCVs drained into cavernous sinus or sphnoparietal sinus.③Aside from SMCV,the bridging veins draining the lateral and basal surface of frontal lobe and temporal lobe,basal vein of Rosenthal and its tributaries were found on the venograms obtained by CE-MRV and TOF-MRV.④The number of SMCV was 1.4 and 1.3 respectively,the diameter of SMCV was 3.7mm and 3.9mm respectively.There are no difference about SMCV on the venograms obtained by CE-MRV and TOF-MRV. 4.The torcular Herophili①According to the relation among the sinus in the region of the torcular Herophili,all subjects in this study could be grouped into 5 types:TypeⅠ, a confluence of sinuses existed;TypeⅡ,the superior sagittal sinus and the straight sinus forked,and the forking of both sinuses joined to form the lateral sinuses;TypeⅢ, the superior sagittal sinus equally drained into two lateral trasverse sinus,the straight sinus drained into one side.TypeⅣ,he straight sinus drained into two lateral trasverse sinus,the superior sagittal sinus drained into one side.TypeⅤ,the sagittal sinus drained into one side and the straight sinus drained into the other.②There were no difference to find TypeⅠ(6%,6%)and TypeⅣ(38%,44%) with CE-MRV and TOF-MRV.There were difference to find TypeⅡ(56%,0%)and TypeⅢ(25%,19%) with CE-MRV and TOF-MRV.③Trasverse sinuse of the right side drainage was mostly found in TypeⅣ, equal drainage was mostly found in TypeⅡ.Conclusion①there were no difference about the study of the cerebral bridging veins on the venograms obtained by CE-MRV and TOF-MRV;there were different about the types of the orcular Herophili;②study the cerebral bridging veins systematically and comprehensively,which enrich image knowledge:③study the imaging features,which helps to preserve bridging veins in neurosurgical planning and procedure to avoid postoperative complications and helps to diagnose cerebral venous diseases accurately and timely;④MRV are efficient modes to preoperative angiographic evaluation and angiographic diagnosis of cerebral venous diseases;TOF-MRV is a good method for preoperative congiographic evaluation about bridging veins;CE-MRV is more time and accurate in angiographic diagnosis of cerebral venous diseases than TOF-MRV.