No.3 2014.2.25 消化系统七年制3

1肝脏疾病2Livercirrhosis•病因：肝炎、血吸虫、酒精中毒、营养不良、慢性胆道梗阻•肝功能损害和门静脉高压•早期无症状，晚期可有腹水、脾肿大、食管静脉曲张、上消化道大出血、黄疸、肝昏迷等•病理生理基础：门脉性、坏死性、胆汁性3肝硬化(cirrhosis)•肝硬化早期可无影像学改变•CT与MRI–体积改变–轮廓改变–肝门、肝裂增宽–左右叶比例失调–脾增大（大于5个肋单元）–门脉高压征象–腹水4•ThepatientwithcirrhosisinearlystagemayhavenoanychangesonCTandMR.–Theliverbecomeshepatomegalyinearlystageandhepatatrophyinlatestage.–Thecontourofthelivermaybewave-like.–Theratiooftherighttotheleftlobisabnormal–Theportalhepatis’or/andliverfissura’sspacesbecomewide–Splenomegaly(alwaysexceedsfiveribunits)cirrhosis56肝硬化、门-脐静脉分流、肝癌7血吸虫肝硬化89肝脓肿(liverabscess)•Clinicandpathology–Liverabscessmaybebacterialoramoebicabscess.–Maybesolitaryormultiplelesions.–Theclinicalsymptomsincludefever,hepatomegalyor/andhepaticregionpain.–WBC↑•临床与病理：–细菌性肝脓肿、阿米巴脓肿–单发或多发–临床症状主要为发热、肝肿大和肝区疼痛–白细胞计数增加10影像学表现•liverabscesshavenocharacteristicsonX-rayplainfilm•CT：Onplainscanning,liverabscessisrevealedbycircularorellipticallowdensitywithCTvaluefrom20~40Hu.Thereisacircularzoneintheabscesswall,whosedensityishigherthanthatofabscesscavitybutlowerthanthatofthenormalliverparenchyma.OncontrastCTimaging,itwasenhancedbycircularorrimenhancement,theremayexistanedemazonesurroundingthelesion(hypodense).Theinnerwallofthecavityisverysmoothandthethicknessishomogeneous.Ifthereisairorairfluidlevelinthecavity,thediagnosisisveryeasy.11•X线平片:缺乏特征•CT病灶呈圆形或椭圆形的，低密度区，CT值20~40Hu，脓肿壁呈环形带，密度高于脓腔、低于正常肝。增强时环形强化，轮廓光整，厚度均匀，外周有低密度水肿带。三环、双环、单环结构。如有气体或液平面可确诊。12•MRI–OnunenhancedT1WI,thelesionisrepresentedbyacircularlowsignalwithaclearmargin,andhighsignalonT2WIwithacircularlowersignalsurroundingit.Oncontrastimaging,itisrevealedbycircularenhancementwithasmoothinnerwallandthewall’sthicknessishomogeneous.–平扫时T1WI呈圆形、边清的低信号，周围有一圈稍低信号影，T2WI病灶呈高信号，周围仍见一圈低信号环；增强时环形强化，厚度均匀，轮廓光滑，脓腔无强化。1314CToftheliverfollowingintravenouscontrastmediuminjection.Liverabscesswithair-fluidlevel.15Contrast-enhancedCToftheupperabdomen.Thereisathick-walledcavitywithpolylobulatedcontourandinhomogeneousattenuationofcontents.Theconcentrichypo-attenuatingrimaroundtheexteriorborderofthelesionmaycorrespondtocompressionoredemaofliverparenchymasurroundingtheabscess.1617CT导引下肝脓肿穿刺引流18女，23岁，分娩2周，高热，右上腹胀痛19引流一周后复查置管引流20肝囊肿(livercyst)•Livercystmaybesingleormultilesions可单发或多发•Themostpatientshavenoclinicalsymptoms.多无临床症状•Itmayexisttogetherwiththecystsinkidney,spleen,pancreasandsoon.可与肾、脾、胰等其它器官囊肿并存21CT•Plainscan:itisrevealedbysingleormultiroundwaterydensitywithasmoothrimwithCTvaluefrom0-20Hu.平扫：单、多发圆形低密度影，边缘清楚光滑，CT值与水接近，0-20Hu。•Contraststudy:Thelesionisnoenhanced.增强：无强化22MRI•平扫：T1WI明显低信号，T2WI明显高信号•增强：信号不增强2324多囊肝25T1WI-axialT2WI-axialT1WI-coronal26肝海绵状血管瘤(cavernoushemangiomaoftheliver)Clinicandpathology•Nosymptomsinmostpatients.•MostlesionswasfoundbyUSGoccasionally.•Thesizeoflesionsisvariety,maybesmallorverylarge.•Thenumber:solitaryormultiplenodes.•Thelesionismainlyconsistedofbloodantrum.27plainCTscanningThelesion’shape：round,globularornodulardensity：low，thecoreofthelesionmaybemorelowerboundary:withaclearedgePresentationsonCT28arterialphasetheenhancementpatternmaybeglobularorperipheralvascularlakes,rapidlyfollowedbyprogressiveopacificationofthecentralportionsofthehaemangioma.portalphasethewholelesionismarkedlyenhancedrelativetotheliver.delayedphaseafterinjectionthemedium10-30minutes,isodensity,thelesionmaydisappear.Thedistinguishedfeatureis“washinrapidlyandwashoutslowly”.contrastCT29平扫：单发或多发，呈类圆形低密度影，边缘清楚，密度均匀，较大病灶其中心密度更低。增强：动脉期可见边缘呈结节状或小片状强化，渐向中心扩展；强化幅度高，病灶的强化密度与动脉血管的密度相近似。静脉期：病灶继续强化，其密度明显高于周围肝实质密度。延迟扫描：仍可有对比剂充填，病变密度与肝脏密度相一致，病变影消失，故有“快进慢出”特点。病灶中心的血栓或纤维化可以始终不强化。CT影像学表现30CTfollowingintravenouscontrastmediumadministrationat20sec,40sec,1minute,3minutesrespectively.Earlyclearenhancementofperipheralvascularlakesisrapidlyfollowedbyprogressiveopacificationofthecentralportionsofthehaemangioma.At3minutesfollowingcontrastinjection,thewholelesionismarkedlyenhancedrelativetotheliver.31unenhancedCTarterial-phaseportal-phasedelayed-phase单发32多发33MRI•Thelesionishypo-signalonT1-weightedimagingT1WI呈稍低信号•Thelesionishyper-signalonT2-weightedimaging,andthesignalincreasesuptoorexceedingthesignalofthegallbladderfollowingextendingthetimeofecho.OnT2-weightedimagingwithlongtimeofecho,thelesion’ssignalismuchhigher,whichiscalled“lightbulb”sign.T2WI呈随回波时间(TE)延长，信号强度递增，直至达到超过胆囊信号，在重T2WI信号强度更高，称“灯泡征”。34T2-weightedimagingTE：60msT2-weightedimagingTE：120msT2-weightedimagingTE：20msT1-weightedimaging35T1WINPWIT2WI肝海绵状血管瘤36肝脏多发小血管瘤37T1WIT2WI动脉期延迟3min延迟5min38肝细胞肝癌（hepatocellularcarcinoma)•Thepatientsarealwaysaccompaniedwithchronichepatitisorcirrhosis.(多发生在慢性肝炎和肝硬化基础上)39hepatocellularcarcinoma•Hepatocellularcarcinomaisthemostcommonprimarymalignancyoftheliver.•Riskfactorsincludecirrhosis,chronichepatitis,andavarietyofcarcinogens.•Hepatomademonstratesthreemajorgrowthpatternsthataffecttheirimagingappearance:diffuseinfiltrative,solitarymassive,andmultinodular.40肝细胞癌(hepatocellularcarcinoma,HCC)临床与病理–80%合并肝硬化–AFP阳性率小肝癌±50%、大肝癌±70%–早期多无症状，中晚期可有腹胀、肝区疼痛、消瘦–肝脾肿大，腹水、黄疸、上消化道出血，为晚期–扩散与转移41肝癌的分型●结节型：肿瘤呈结节状，与周围境界清楚，可有纤维包膜，一般情况下，早期无或极少向被膜外侵犯和形成门静脉瘤栓，此型约占肝癌的1/2~2/3。单结节型：单个结