肝脓肿与血肿课件

BENIGNFOCALLIVERLESIONSAbscessesandHaematomaClinicalfeaturesofanabscess(脓肿)Patientspresentwithfever,oftenaccompaniedbyrightupperquadrant(RUQ)painandvomiting（呕吐）.Abnormalliverfunctiontests(LFTs)andanaemia（贫血）canalsobepresent.Theclinicalhistoryhelpsthesonographer（超声医生）toestablishthenatureofthefocallesionandaetiologyoftheabscess.Abscessesofanytypemaybesolitaryormultiple.Becausetheultrasoundappearancesofabscessescanbesimilartothoseofnecrotic（坏死的）tumoursorhaematoma（血肿）,theclinicalpictureisofparticularimportancetothesonographer.UltrasoundappearancesHepaticabscessesmaydisplayavarietyofacousticfeatures.Theirinternalappearancesvaryconsiderably.Intheveryearlystagesthereisazoneofinfected,oedematous（水肿的）livertissuewhichappearsonultrasoundasahypoechoic,solidfocallesion.Astheinfectiondevelops,thelivertissuebecomesnecrotic（坏死的）andliquefactiontakesplace.Theabscessmaystillappearfullofhomogeneousechoesfrompusandcanbemistakenforasolidlesion,butasitprogresses,thefluidcontentmaybecomeapparent,usuallywithconsiderabledebris（碎片）withinit.Becausetheyarefluid-filled,abscessesdemonstrateposteriorenhancement(Fig.4.7A).Themarginsofanabscessareirregularandoftenill-definedandfrequentlythickened.Theinflammatorycapsuleoftheabscessmaydemonstratevascularity（多血管）oncolourorpowerDopplerbutthisisnotinvariableanddependsonequipmentsensitivityandsizeofthelesion.Infectionwithgas-formingorganismsmayaccountforthepresenceofgaswithinsomeliverabscesses(Fig.4.7B).Thegascontainedwithinthislargeabscessintherightlobeoftheliverobscuresthefullextentofthelesion.(Largeabscesseslikethis,whichcontaingas,maymimictheacousticappearancesofnormalbowel.)TherearethreemaintypesofabscessPyogenicabscess（化脓性脓肿）Amoebicabscess（阿米巴脓肿）Candidiasisabscess（念珠菌脓肿）PyogenicabscessTheseformasaresultofinfectionenteringtheliverthroughtheportalvenoussystem(门静脉系统).Mostcommonly,appendiceal（阑尾的）ordiverticular（憩室的）abscessesareresponsible,butintrahepaticabscessesarealsoseeninimmunosuppressed（免疫抑制的）patientsandfollowingpostoperativeinfection.Theyarefrequentlymultiple,andthepatientmustbecloselymonitoredafterdiagnosistopreventrapidspread.Pyogenicabscessisstillconsideredalethal（致命的）condition,whichhasincreasedinrecentyearsduetoincreasinglyaggressivesurgicalapproachestomanyabdominalneoplasms.4AmoebicabscessThisisaparasitic（寄生虫的）infectionwhichisrareintheUK,butfoundfrequentlyinpartsofAfrica,IndiaandthesouthernpartsoftheUSA.Suspicionshouldberaisedwhenthepatienthasvisitedthesecountries.Itisusuallycontractedbydrinkingcontaminatedwater（污水）andinfectsthecolon（结肠）,ulceratingthewallandsubsequentlybeingtransportedtotheliverviatheportalvenoussystem.ManagementofhepaticabscessesAnultrasound-guidedaspiration（吸引术）toobtainpusforcultureisusefulforidentifyingtheresponsibleorganism.Aspirationcombinedwithantibiotictherapyisusuallyhighlysuccessfulforsmallerabscessesandultrasoundisusedtomonitortheresolutionoftheabscessesintheliver.Ultrasound-guideddrainageisusedforlargelesions,andsurgicalremovalisrarelyrequired.Furtherradiologymaybeindicatedtoestablishtheunderlyingcauseandextent,forexamplebariumenema（钡剂灌肠）orCT,particularlyifamoebicinfectionissuspected.HaematomaTheliverhaematomamayhavesimilaracousticappearancestothoseofanabscess,butdoesnotsharethesameclinicalfeatures.Ahaematomaistheresultoftrauma（创伤）(usually,therefore,viatheAccidentandEmergencydepartment)butthetraumamayalsobeiatrogenic（医源性）,forexamplefollowingabiopsy（活检）procedure(hencethevalueofusingultrasoundguidancetoavoidmajorvesselsintheliver)orsurgery.Intrahepatichaematomafollowingaroadtrafficaccidentwithribfractures.Thelesionisrelativelyfreshandcontainssomelow-levelechoes.2-day-oldsubcapsularhaematoma.Thecollectionbecameprogressivelysmallerandhyper