Acute cerebral hemorrhage magnetic resonance diffusionweighted imaging毕业论文翻译.docx

Acute cerebral hemorrhage magnetic resonance diffusionweighted imaging毕业论文翻译.docx

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Acutecerebralhemorrhagemagneticresonancediffusionweightedimaging毕业论文翻译

Acutecerebralhemorrhagemagneticresonancediffusion-weightedimaging

[Abstract]ObjectiveToinvestigatetheacutecerebralhemorrhage,magneticresonancediffusion-weightedimaging（DWI）intheperformanceofitsmechanism.Methodsofclinicalsymptomsafter12h,expertDWIexamination17casesofacutecerebralhemorrhage,thepatient’sDWIandADCmapswereobserved17casesofacutecerebralhemorrhageonDWIninecasesshowedlowsignalforthecentral,peripheralirregularhighsignal;6casesshowedhomogeneoushighsignalforthecentral,peripheral,seethelowsignal,twocasesofperformanceforhighandlowmixedsignalwhenb=0basecollectionlikethe11casesshowedlowsignal,ofwhichsixcasesoflowsignalregioncanbeseenintermingledwiththehighsignal,sixcasesshowedisointensesignalaroundseeirregularringoflowsignalontheADCmap15casesshowedhomogeneouslowsignal.conclusionscombinedwithADCmapsandb=0thebasisofacquisitionlikethatDWIisabletomakeanaccuratediagnosisofacutecerebralhemorrhage,

Keywordsmagneticresonanceimaging,diffusecerebralhemorrhagediagnosis[ABSTRACT]ObjectiveToinvestigatethemanifestationsandmechanismofacuteintracerebralhemorrhageondiffusionweightedMRimaging（DWI）.MethodsDWIwasperformedforpatientswithacuteintracerebralhemorrhage（n=17）within12hoursaftertheonsetofsymptoms.BoththeDWIandADCmapwereanalysedtoinvestigatethemanifestationsandthemechanismofthedisease.ResultsOnDWI,amongthe17patients,ninewerefoundwithlowsignalinthecentreandirregularouterhighsignal,sixwithmiddleinhomogeneoushighsignalandsurroundinglowsignal,andtwowithmixedsignal.OntheDWI（b=0）,obviouslowsignalswerefoundin11patientsofwhomisoorhighsignalswerealsofoundinthelowsignalareainsixpatients,inisointensitywithsurroundingirregularlowsignal.FifteenpatientswithinhomogeneouslowsignalwerefoundonADCmap.ConclusionCombinedwithADCmapandtheDWI（b=0）,accuratediagnosisofacuteintracerebralhemorrhagecouldbemadebydiffusionweightedMRimaging.

[KEYWORDS]thediffusionofmagneticresonanceimaging;cerebralhemorrhage,diagnosisMagneticresonancediffusion-weightedimaging（DWIhasbeenwidelyusedinacute,thediagnosisofhyperacutecerebralinfarction,abouttheessenceofacutecerebralhemorrhageDWIperformanceofdomestic,foreignandarerarelyreported[1,2].Duetoacutecerebralhemorrhage,andacutebrainsimilarclinicalsymptomsofinfarction,treatmentiscompletelydifferent,andthereforeveryimportanttodistinguishbetweenthetwo.DWImanifestationsofacutecerebralhemorrhage,wereobserved,anditsmechanismarediscussed.

Anobjectandmethod1.1GeneralInformationThisgroup,17casesofacutecerebralhemorrhage,thepatientsintheclinicalsymptomsfor12hwithinmagneticresonance（MRexamination,andareexpertsinMRimaging15minafterCTexaminationconfirmed11casesweremaleand6females,aged46to69yearsold,average58.7yearsold.

1.2theMRcheckDWIexaminationtheSiemens1.5TwholebodyMRimagingsystem（MagnetomSonata,SyngotheMR2000Bstandardheadcoil.Scanparameters:

TR=3of100ms,TE=96ms,slicethickness5mm,theintervalof1mm,FOV=230mm×201mm,matrix128×128.

DWIsequencesselectedthreedirectionsimaging（b=0,1000s/mm2,thediffusiongradientwereimposedonthelevelselectandfrequencyencodingandphaseencodingdirection,on-linetogeneratethetraceDWI,mapandtraceADCmapcanbedirectlymeasuredintheADCimagesregionsofinterest（ROIapparentdiffusioncoefficient（ADC.

1.3CTexaminationUsingtheSiemensSensation16-slicespiralCTscanner.Scanparameters:

120kV,200mA,slicethickness10mm,anintervalof10mm,matrix256×256.

2results2.1CTmanifestationsof17casesofacutecerebralhemorrhageinthebasalgangliaarea,10casesinwhichtherightside,leftsideofthesevencases.OnCTshowedaroundorovalhigh-density,uniformdensity,CTvalue（75.1+-6.7Huperipheraledema,andadjacentstructuresseenunderpressuretoshift.

2.2DWI,performanceOnDWI,9casesshowedlowsignalforthecentral,peripheralirregularhighsignal,sixcasesmanifestedascentralheterogeneoushighsignal,thesurroundingofthelowsignalperformanceinthetwocasesofhighandlowmixedsignals.

Thebasisofacquisitionb=0images,11casesshowedlowsignal,ofwhichsixcasesoflowsignalareaseenintermingledwiththehighsignal,sixcasesshowedisointensesignal,surroundedinanirregularlowsignalring.

OntheADCmap,15casesshowedhomogeneouslowsignaltwocasestheperformanceofhighandlowmixedsignals,amongwhich12casesseenintheperipheralirregularhighsignal,themeanADCvaluewithinthehematoma（41.98+-16.96×10-5mm2/s,andacutecerebralinfarctionareameanADCvalueofanotherstudy,（45.07+-11.13）×10-5mm2/s,thedifferencewasnotstatisticallysignificant（t=1.053,P>0.05peripheraledema,themeanADCvalueof（128.40+-20.97×10-5mm2/s,.

3todiscussIsgenerallybelievedthatCTsensitivitytoacutecerebralhemorrhage,ishigherthanMRI,conventionalMRisdifficulttodiagnosebleedingwithin24h,thustheconventionalCTismorecommonlyusedfordiagnosisofcerebralhemorrhage[3]However,withMRrecognizethevalueofassessmentofacuteischemicstrokeandthepopularityoftheMRexamination,whethertheapplicationofMRstrokesuspectedpatientsone-stopdiagnosisbecomeafocusofattentionofneuroradiologistshavetoavoidthefirstCTscantoexcludehemorrhagicstrokeMRexaminationtoassessacuteischemicstrokehasbeenshownthatthroughtherationalapplicationofMRimagingtechniquesforthedetectionofdifferenttypesofintracranialhemorrhage,thevalueofMRandCTarequitethanCTmoresensitive,especiallyforthehardmembrane,subarachnoidandintraventricularhemorrhage[4-6].

OntheassessedvalueofDWIforacute,hyperacuteischemicstrokehasbeenverypositive,butlessonDWI,thediagnosticvalueofbrainhemorrhage,andthenumberofcasesinvolvedrarely[1,7]isgenerallyconsideredacutecerebralhemorrhageADCvalues​​decline,mainlyashighsignalonDWI,theproliferationofdeclineseeninaheterogeneouslow-signalcomponentsofhighsignalmayberelatedtocontractionofbloodclotsrelatedtothecompositionofthelowsignalgeneratedbydeoxyhemoglobin.DWIperformanceofbleedinginthisstudyisnotcompletelyconsistentwiththeliterature,onlysixcasesinDWIshowedheterogeneoushighsignalontheADCmapshowedlowsignal.patientsshowedthecentrallowsignalintensityonDWI,thesurroundingringorirregularhighsignalontheADCmap,expressedasthelowsignalofthecentralarea,thesurroundingringofhighsignal.ninecasesofbleedingvolumelessobviouslowsignalonDWIwhenb=0,maybeoxygenatedHaemoglobinhasbeencompletelyormostoftheconversionofdeoxy-hemoglobin,lowsignalonDWI,notonlywiththespreadofthedecreaseoftheparamagneticeffectofdeoxyhemoglobin.lesionssurroundinghighsignalmaybecausedbybleedingaroundthebraintissueedema.alsoshowsthattheconversionofoxygenatedhemoglobintodeoxygenatedhemoglobinintheacutestageofcerebralhemorrhage1casesofthisarticleheterogeneoussignalintensityonDWIperformance,mixedsignalontheADCmap,thelowestADCvalueof.304×10-3mm2/s,whileupto1.052×10-3mm2/s,indicatingthattheriseofthelocalADCvalues​​maythebleedingareainthepastexistenceofcerebralmalaciarelated.

Linksinthefreepaperdownloadthecenter

gradientechosequenceusingtheflipreadoutgradientinsteadof180°compositeRFpulseecho,andthereforecauseforthebleedingofparamagnetichighlysensitivetomagneticfieldinhomogeneity.hematomaonthegradientechosequencewillresultinlowsignalarea,therangeissignificantlygreaterthanconventionalT2-weightedimages.StudieshaveshownthatconventionalMRspinechosequencewithgradientechosequencecombinedwithMRIandCTfordiagnosisofacutebleeding[8-11].MRIindeterminingtheetiologyofacutecerebralhemorrhageissuperiortoCTforcerebralarteriovenousmalformations,aneurysmshaveaveryimportantvalue.b=0DWIimage（EPIT2*WIhasagradientechosequencesensitivefeaturesofbleeding,thisstudyof17cases11casesofcerebralhemorrhagewaslowsignal,sixcasesoflowsignalring.Inaddition,theEPIT2*WIsequencescantimewassignificantlyshorterthanthegradientechosequence,intheory,shouldbesuitableforthediagnosisofacutecerebralhemorrhage,buttheEPIT2*WI,duetothelowspatialresolutionintheEPIT2*WI,hasbeenreportedintheliterature,thesensitivityofcerebralhemorrhagelessthanthegradientechosequence[12]Webelievethattheapparentrestlessnessofthepatient,considerusingtheEPItheT2*WIsequence,theuseofitshightemporalresolutiontoremovetheartifactscausedbytheactivitiesoftheassessmentofcerebralhemorrhage.Inaddition,theapplicationofgradientechosequencesorEPIT2*WI,shouldalsoberecognizedthatthissequenceitselfsomelimitations,duetotheparamagneticeffectisparticularlysensitivearoundtheposteriorfossa,paranasalsinuses,orskullbaseneartheobviousartifactsandthediagnosisofthesepartsofthebleedingshouldbeespeciallycarefultoavoidfalsepositiveerrors.

ThisstudyalsoshowedthatthesimplemeasurementofADCvalues​​cannotdirectlyidentifytheessenceofacutecerebralhemorrhageand