搜索
ImagingLesionsoftheCavernousSinus海绵窦区病变白洁2011-08-31•Thecavernoussinus(CS)containsvitalneurovascularstructuresthatmaybeaffectedbyvascular,neoplastic,infective,andinfiltrativelesionsarisingintheCSproperorviaextensionfromadjacentintra-andextracranialregions•海绵窦有重要的神经血管结构，可发生海绵窦本身固有的或由临近的颅内外结构延伸至海绵窦的血管、肿瘤、感染或浸润性病变•PatientswithCSsyndromeusuallypresentwithparesisof1ormorecranialnerves(III-VI),whichmaybeassociatedwithpainfulophthalmoplegia•TheclinicianneedstoknowthetypeofCSlesion,itsrelationshiptocrucialneurovascularstructures,anditsextensionintothesurroundingtissues•Thesefindingsareessentialfordecidingtherapeuticmodalitiessuchasmicrosurgery,radiationtherapy,ormedicaltreatmentaswellasforappropriateplanningofsurgeryorradiationtherapy•有海绵窦综合征的患者常有一支或多支颅神经麻痹（III-VI），可伴有痛性眼肌麻痹•临床医生需了解海绵窦病变的类型、与重要神经血管结构的关系、有无延伸至临近组织•这对于决定治疗方式是必要的，如显微外科手术、放疗或内科治疗，以及制定适当的外科或放疗计划ImagingProtocol影像学检查•RoutineT2,FLAIR,andprecontrastT1WIoftheentirebrain•Post-contrastT1WI3-mm-thickimagesoftheaxialandcoronalplaneswithatleast1planeimagedwithafat-saturationtechnique•Thin-section3DheavilyT2-weightedimagesmayallowvisualizationofindividualcranialnervesintheCSandadjacentcisterns•全脑的常规T2WI、FLAIR、平扫T1WI•轴位和冠状位的增强扫描，3mm层厚，至少一个切面为压脂像•薄层3D重T2WI成像，可使每一根颅神经和临近的脑池显像•CTisbestperformedbyusingamultidetectorscannerafterintravenousadministrationofiodinatedcontrastmedium.•Acquisitionsinaxialorcoronalplanesbyusing1-mm-thicksectionsmaybeobtainedandthenreformattedinotherplanes•CT扫描最好使用多探测器仪器的增强扫描•采集1mm层厚的轴位或冠状位信息，并可其他方位重建Anatomy解剖•TheCSiscomposedof2layersofdurathatsplittoformaseptatevenouschannel•海绵窦是有2层硬脑膜分隔形成的静脉通道•EachduralwallcontainsanouterlayerapposedtoboneandaninnerlayerincontactwithbloodorCSF•每层硬脑膜由靠近颅骨的外层和临近血液/脑脊液的内层组成•TheCSextendsfromtheorbitalapex眶尖andsuperiororbitalfissure眶上裂anteriorlytotheMeckelcaveandfartherposteriorlytotheduraandtheporesthatallownervestoenterit•Transversediameteris5–7mm左右径5–7mm•Verticaldiameteris5–8mm上下径5–8mm•Anteroposteriordiameteris10–15mm前后径10–15mm•TheCSiscomposedofanetworkofsmallvenouschannelsthatmayarbitrarilybedividedintodifferentcompartments•内有小静脉通道组成的网，能任意分成不同的间隔•ThemainvenousinfluxintotheCSisthesuperiorandinferiorophthalmicveins,pterygoidplexus,andSylvianvein•进入海绵窦的主要静脉是眼上静脉和眼下静脉、翼丛、侧裂静脉•TheoutflowoftheCSoccursviathesuperiorandinferiorpetrosalsinuses•经岩上窦、岩下窦流出海绵窦•Theinternalcarotidartery(ICA)isthemostmedialstructureinsidetheCSandiscontainedintheso-calledcarotidtrigone•颈内动脉位于海绵窦的中间，并位于所谓的颈动脉三角内•CranialnervesIIIandIVandthefirstandseconddivisionsofthecranialnerveV(fromsuperiortoinferior)arelocatedinthelateralduralwalloftheCS(calledtheoculomotortrigone)•动眼神经、滑车神经、三叉神经的第1、2分支（眼神经和上颌神经）位于海绵窦的侧壁（称为动眼神经三角）•CranialnerveVcoursesinthecentralpartoftheCSinferolateraltotheICA•三叉神经走行与海绵窦的中部，位于颈内动脉的下方•TheCSisamultiseptatespace,whichshowsintensecontrastenhancementoftheslowerflowingvenousblood•海绵窦是一个多分隔的空间，由于慢流速的静脉血而增强后能明显强化•TheICAappearsasasignal-intensityvoidstructure•颈内动脉则表现为血管流空信号•Occasionally,theCSmaycontainfattydepositsthatarenormal–ThesefattyzonesmaybemoreprominentinobesepatientsorthosewithCushingsyndromeorreceivingexogenoussteroidtherapy•偶尔，海绵窦可见脂肪沉积，这是正常表现–这些脂肪沉积的区域更常见于肥胖患者、库欣综合征患者、接受外源性甾类激素治疗的患者Normalfatdeposits正常的脂肪沉积AxialnoncontrastCTscanshowsnormalandincidentallyfounddepositsoffat(arrowheads)intheposteriorCSsCT平扫可见海绵窦后部的脂肪沉积，少见但为正常•Meckel腔–Meckel腔（Meckelcave，MC）为颅中窝中后份的硬脑膜陷窝，区域狭小、空间结构复杂并与许多重要神经、血管结构相毗邻–三叉神经根由桥脑发出后,从岩上窦下方穿小脑幕的三叉神经孔至三叉神经节，在这段距离之前，三叉神经根与脑膜的关系酷似脊神经根与脊膜鞘的关系，其外覆盖着硬脑膜和蛛网膜，并形成一腔隙，称为Meckel腔–Meckel腔为由颅后窝向颅中窝后内侧部分突入的硬脑膜陷凹，分为上、下、前、后壁及内、外侧壁•前壁和上壁与海绵窦后部静脉间隙相邻；外侧壁与颅中窝内侧壁硬脑膜相邻，内侧壁前部与颈内动脉海绵窦段后升部相邻，并夹第四对颅神经，也有少量结缔组织相连；内侧壁后部与颞骨岩尖部的骨膜相贴•三叉神经节位于Meckel腔内，呈半月形或三角形，其表面覆盖蛛网膜，后者包绕三叉神经形成蛛网膜下腔的三叉池•半月神经节位于中颅凹的后内侧，由关系密切的三种间隙围绕:三叉神经池、Meckel腔和海绵窦硬膜外间隙•蛛网膜包裹三叉神经节，与三叉神经节之间有一定的间隙，松散的三叉神经节纤维之间也有一定的间隙，共同构成三叉池•三叉神经池与邻近蛛网膜间隙相连，脑池造影时可被充盈•海绵窦间隙位于形成中颅凹内侧壁的固有硬膜和蝶骨骨膜和岩骨尖之间•Schwannoma神经鞘瘤•PlexiformNeurofibroma丛状神经纤维瘤•MalignantPeripheralNerveSheathTumor恶性周围神经鞘瘤•CavernousHemangioma海绵状血管瘤•Meningioma脑膜瘤•PituitaryAdenoma垂体瘤•Melanocytoma黑色素细胞瘤•Chordoma脊索瘤•Chondrosarcoma软骨肉瘤•NasopharyngealCarcinoma鼻咽癌•JuvenileAngiofibroma幼年血管纤维瘤•SphenoidSinusCarcinoma蝶窦癌•Rhabdomyosarcoma横纹肌肉瘤•Metastases转移瘤•LymphomaandLeukemia淋巴瘤和白血病•PosttransplantationLymphoproliferativeDisorder移植术后淋巴组织增生•EpidermoidandDermoidCysts表皮或皮样囊肿•DisordersofHistiocyteProliferation组织细胞增生症NeoplasticLesions肿瘤性病变•Schwannoma神经鞘瘤–AtrigeminalnerveschwannomacommonlyinvolvestheCSand,in50%ofinstances,hasatypicaldumbbell-shapewithbulkytumorintheMeckelcaveandtheprepontinecisternwithawaistattheporoustrigeminus–三叉神经鞘瘤在最常见，发病率约50%，典型的哑铃样形状，Meckel腔和桥前池的肿块+腰部位于三叉神经孔–Conversely,itmaybefoundonlyinvolvingtheMeckelcave–也可以仅仅累及Meckel腔–Itmaybesolidorhavevariablecysticorhemorrhagiccomponentswithoccasionalfluidlevels–肿瘤可以是实性的，也可以有多样的囊变或出血，偶见液平–Smalltumorstendtobehomogeneous,whereaslargeonesarefrequentlyheterogeneousinappearance–肿瘤体积小则多质地均匀，体积大的肿瘤多为非均质性表现–Schwannomasareisointense-to-hypointensemassesonT1images,mostlyT2hyperintense,andshowcontrastenhancement–神经鞘瘤T1WE多为等或低信号，T2WI多为高信号，增强后有强化–Acluetothediagnosisisthattheyfollowtheexpect