脑包虫病细粒棘球绦虫感染MRI诊断227

Cerebralhydatiddisease-EchinococcusgranulosusinfectionMRIdiagnose

脑包虫病-细粒棘球绦虫感染MRI诊断

2012.2.27概述HydatiddiseaseisaworldwidezoonosisproducedbythelarvalstageoftheEchinococcustapeworm.包虫病是一种流行于全世界范围的动物源性寄生虫病，主要是由棘球绦虫幼虫所引发。ThetwomaintypesofhydatiddiseasearecausedbyEgranulosusandEmultilocularis.Egranulosusisthemorecommontype.引发包虫病的两种主要的寄生虫类型分别是细粒棘球绦虫和多房棘球绦虫，细粒棘球绦虫更常见。whereasEmultilocularisislesscommonbutmoreinvasive,mimickingamalignancy.多房棘球绦虫少见但侵袭性更强，其表现类似于恶性病变。

ItiscommonlyseeninthegreatgrazingregionsoftheWorld,particularlytheMediterraneanregion,Africa,SouthAmerica,theMiddleEast,Australia,andNewZealand.它常见于世界上的的牧区，特别是地中海区域、非洲、南美、东亚、澳大利亚和新西兰。

Dogsorothercarnivoresaredefinitivehosts,whereassheeporotherruminantsareintermediatehosts.狗或其他的肉食动物是终宿主，而羊或其他的反刍性动物是中间宿主。Humansaresecondarilyinfectedbytheingestionoffoodorwaterthathasbeencontaminatedbydogfecescontainingtheeggsoftheparasite.被包含有寄生虫卵的狗粪所污染的食物或水被人类摄入从而引起继发性感染。

Intracranialgranulosusechinococcosisoccursinonlyapproximately2%ofcasesofhydatiddisease.颅内的细粒棘球绦虫感染仅见于约2％的包虫病病例。

typicallyinvolvingthecerebralparenchyma,especiallytheparietallobes,correspondingtothemiddlecerebralarterywatershedterritory.IntracranialsubarachnoidspacesarethesecondmostcommonlocationofthediseaseintheCNS,althoughtheiroccurrenceisfarlessfrequent.

通常累及大脑实质，特别是顶叶，符合大脑中动脉分水岭区，颅内的蛛网膜下腔是第二好发部位。Casesofcerebralaqueductcyst,giganticcystarisingfromthediploeofcranialboneswithintracranialextension,andintraduralspinalhydatidcystshavebeenreported.发生于大脑导水管的囊肿、起源于颅骨板障并延伸至颅内的巨大囊肿、以及椎管内硬膜下囊肿都有报道。

Cystsareusuallysingleandmaybeunilocularormultilocular.囊肿常常是单发的，可以是单房或多房。

Cerebralhydatidcystisgenerallysolitarybutmaybemultiplewhenitrupturesspontaneouslyorduetotraumaorsurgery.脑包虫囊肿通常是单囊的,当它自发破裂或由于外伤或手术而成为多囊。Multivesicularcystsarerareinthebrain.Calcificationoccursinlessthan1%ofcases.颅内的多囊状病变是相当少的，不超过1％的病例可以出现钙化。

MRI表现ContrastenhancedMRIshowslackofenhancementofthecystwalls.增强MRI囊壁无强化。Intracranialgranulosusechinococcosisoccursinonlyapproximately2%ofcasesofhydatiddisease.颅内的细粒棘球绦虫感染仅见于约2％的包虫病病例。

E.granulosusinfectionofthebrainpresentswithoneormorehomogeneous,thin-walledcysts.颅脑细粒棘球绦虫感染表现为一个或多个均匀的薄壁囊肿。诊断要点Cystsignalisisointenserelativetocerebrospinalfluid.囊肿的信号与脑脊液信号相似。Thecystwalltypicallylacksgadoliniumenhancement.囊壁通常无强化。

Usuallythereisnoperilesionaledema.通常没有瘤周水肿。实验室检查X-ray,hydatidpatientstheliver,lungs,bonesinspection,allcanfindcalcification.X线检查，包虫患者肝、肺、骨骼检查，均可发现钙化。DSAcheck,itsspecialperformanceforlesions

withoutbloodvessels,thebloodvesselsofthecapsulearoundhydatidextremeshift,straight,aroundintothespherical.DSA检查，其特殊表现为病变区无血管、围绕包虫囊的血管极度移位、变直、环绕成球形。其它影像学检查CTandMRIscansforbrainechinococcosishighlycharacteristic,performanceforcysticsphericalandborderslesions.CT与MRI扫描对脑包虫病具有高度特征性，表现为囊性球形病变，边界清楚；Densityandsignalandcerebrospinalfluidissimilar,nolesionsedgeedema,noenhancementandbrainabscesses,cysticbraintumororarachnoidcyst.密度与信号与脑脊液相似，无病灶边缘水肿，无增强，可与脑脓肿、囊性脑瘤或蛛网膜囊肿等鉴别。Completeremovalcyst.完整摘除囊肿。

Bursawallisthin,canspendpartofliquidwerefirstandthenremovebursawall.囊壁较薄者，可先抽出部分囊液，然后摘除囊壁。S