MR Venographic Study Of The Tentorial Sinus,falcine Sinus And Occipital Sinus Using Three-dimensional Visualization Technology

Part Ⅰ MR venographic study of the tentorial sinus and bridging veins base on three-dimensional visualization technology【Objective】To observe the morphological characteristics of tentorial sinus and bridging veins of tentorium using three-dimensional visualization technology based on CE-MRV,and explore its clinical significance.【Methods】Eighty patients who underwent 3D CE-MRV examination in our hospital from January 2016 to November 2019 were randomly selected,and a 3D reconstruction model of the tentorium-veins was established by the Stealth Viz program in the Stealth Station S7 neuronavigation system.The morphological characteristics of tentorial sinus and bridging veins of tentorium were analyzed.【Results】The tentorial sinus can be divided into medial group,middle group,and lateral group.Their common confluence sites from more to less are the transverse sinus,torcular herophili,straight sinus,and superior petrosal sinus.The middle and posterior part of transverse sinus and torcular herophili are the most common areas of confluence.The bridging veins from above the tentorium can be divided into single stem type,multiple stem type,candelabra type,and venous lakes type.Among them,the multiple stem type is the most common type.The cerebellar bridging veins below the tentorium can be divided into the the tentorial group,torcular herophili group,and petrosal group.The distribution of the bridging vein joining the torcular herophili is relatively concentrated.【Conclusion】Three-dimensional visualization technology can effectively display the venous anatomy of the tentorium area,help to understand the anatomy and drainaging characteristics of the cerebral vein in the tentorium area,and guide the approach design of the operation in this area and the protection of the adjacent bridging veins.Tentorium cerebelli;Part Ⅱ MR venographic study of the intracranial falcine sinus and imaging anatomy base on visualizationtechnology【Objective】To investigate the incidence and imaging anatomical features of falcine sinus in healthy human.【Methods】The data of three-dimensional enhanced magnetic resonance angiography(3D CE-MRV)of 177 healthy patiens(81 males and 96 females)with complete falcine and dural venous sinus were analyzed,and volume rendering technique(VRT)was used to observe the falcine sinus.【Results】The falcine sinus was found in the cerebral falx of 43 patients,of which 37 patients were located at the junction of the middle and posterior one third of the cerebral falx.6 patients were located at the posterior one third of the cerebral falx.According to the structure of the veins connecting to the two ends,the falcine sinus was divided into three types: type Ⅰ(derived from the cerebral falx,injected into the inferior sagittal sinus,vein of Galen or straight sinus),type(derivⅡ ed from the cerebral falx and injected into the posterior part of the superior sagittal sinus)and type Ⅲ(connecting the superior sagittal sinus to the inferior sagittal sinus、vein of Galen or straight sinus).Type I falcine sinus consists of mass-type,triangle-type,strip-type and irregular shape-type.Type II falcine sinus includes straight strip-type and curved strip-type.Type III falcine sinus includes thin strip-type,wide band-type and V-type.The V-type is usually formed by the fusion of type I and type II falcine sinuses.A total of 11 cases of type falcine sinus,21 cases of type falcine sinus Ⅰ Ⅱand 14 cases of type falcine sinus were found(figure 1).Among them,4 patients Ⅲhad type falcine sinus and type falcine sinus simultaneously,6 paⅠ Ⅱ tients had type Ⅱ falcine sinus and type falcine sinus simultaneously,5 patients had double type ⅢⅡ falcine sinus,and 4 patients had triple type falcine sinus in their cerebral falx.Ⅱ【Conclusion】3D CE-MRV combined with VRT is a good method for observing falcine sinus.falcine sinus is not rare and has various types.Part Ⅲ MR venographic study of the intracranial occipital sinus and imaging anatomy base on visualizationtechnology【Objective】To investigate the anatomic characteristics and clinical significance of the occipital sinus by using three-dimensional enhanced magnetic resonance angiography and volume rendering technique.【Methods】The study included 740 healthy patients who underwent CE-MRV between January 2016 and December 2019.The occipital sinus was observed by CE-MRV combined with VRT.The data collected included the age and gender of the patients,the display rate of occipital sinus,anatomical characteristics,types,the distance between occipital sinus and midline,and the communication with connected vessels.【Results】Of the 740 patients,236(31.9%)had occipital sinus.Patients with occipital sinus are 14 to 73 years old,with an average age of 55 years old.107 males(46.9%)and 129 females(53.1%).The occipital sinus can be divided into five types: Type A(micro occipital sinus),Type B1(single occipital sinus located in the midline),Type B2(single occipital sinus deviated from the midline),Type C(double occipital sinus),and Type D(multiple occipital sinus).The most common type of occipital sinus is the Type B1(34.7%).The most common type of occipital sinus was Type A(9.3%).29.6% cases had multiple occipital sinuses.A lower frequency of occipital sinus was observed in subjects younger than 50 years of age.On the cranial and / or caudal sides of occipital sinus,some of occipital sinus are bifurcated and communicate with multiple blood vessels.The length of occipital sinus varies from 8.0mm to 47.0mm,and the width from 2.3mm to 12.6mm.Oblique occipital sinus was found in 31 patients(4.2%),among which 16(51.6%)were accompanied by transverse sinus hypoplastic or aplastic.【Conclusion】3D CE-MRV can be used as a noninvasive method to evaluate the occipital sinus and its related dural sinus.The occipital sinus has a variety of anatomical variations.Some of the occipital sinus replace the transverse sinus as the main drainage way of the intracranial vein.Careful imaging examination can provide useful information for preoperative evaluation of posterior fossa lesions.