《脾臟影像診斷學(xué)》

脾臟

影像診斷學(xué)1編輯ppt脾臟影像檢查技術(shù)X線：價(jià)值有限，血管造影USCT：為更清楚顯示小病變，可應(yīng)用5mm的層厚和層距平掃發(fā)現(xiàn)可疑應(yīng)增強(qiáng)2編輯pptMRImagingTechniqueCoronalT2WIhalf-Fourierrapidacquisitionwithrelaxationenhancement(RARE)AxialFSET2WIorlongechotimeinversion-recoveryimagingperformedduringabreathholdAxialGRET1WIchemicalshiftin-phaseandout-of-phaseimagingperformedduringabreathholdAxial3DGREbreath-holdsequencesuchasvolumetricinterpolatedbreath-holdexamination(VIBE)withpre-contrastanddynamicenhanced3編輯pptMRImagingTechniqueLowerthanliveronT1WIandhigheronT2WIImagesobtainedimmediatelyafterenhancementusuallydemonstratedifferentcirculationsasregionsofalternatinghighandlowsignalintensity,resultinginaserpentineorarciformpatternBecomeshomogeneousapproximately60–90saftercontrastmaterialadministration4編輯pptAnatomyThelargestductlessglandandthelargestsinglelymphaticorganinthebodymesodermalinorigintothecirculatorysystemasthelymphnodesfunctionsincludeimmunologicsurveillance,redbloodcellbreakdown,andspleniccontractionforbloodvolumeaugmentationduringhemorrhageAwiderangeofpathologycanaffectthespleen5編輯pptAnatomyAnintraperitonealorganwithasmoothserosalsurfaceandattachedtotheretroperitoneumbyfattyligamentssurfaces:diaphragmatic(phrenic)andvisceral

VisceralsurfaceisdividedintoananteriororgastricridgeandaposteriororrenalportionSplenicarteryandveinemergefromthesplenichilumintheformofsixormorebranches;thesplenicarteryisremarkableforitslargesizeandtortuosity.slightlysuperiortothevein6編輯pptMicroscopicAnatomydividedintotwocompartments,theredandwhitepulps,separatedbythemarginalzoneThewhitepulpismadeupofTandBlymphocytesandlocatedcentrallyTheredpulpiscomposedofrichplexusesoftortuousvenoussinuses7編輯ppt脾的大小新月形或內(nèi)緣凹陷的半月形，密度均勻略低于肝前后徑7～10㎝寬徑4～6㎝上下徑11～15㎝8編輯ppt動(dòng)脈期強(qiáng)化不均勻

靜脈期和實(shí)質(zhì)期密度逐漸均勻一致10"20"60"30"9編輯pptArciformnormalenhancementpatternAxial3DGREVIBEImmediatelyafteradministrationofcontrastmaterialArciformnormalenhancementpattern10編輯ppt脾的異常CT表現(xiàn)平掃脾增大數(shù)目：多、副、無(wú)密度異常低密度：腫瘤、膿腫、囊腫、梗死、挫傷高密度：外傷血腫、錯(cuò)構(gòu)瘤、鈣化對(duì)比增強(qiáng)病灶強(qiáng)化：血管瘤、淋巴瘤、轉(zhuǎn)移瘤環(huán)狀強(qiáng)化：膿腫病灶無(wú)強(qiáng)化：囊腫、梗死11編輯pptMRI影像分析橫斷面大小、形態(tài)與CT相似冠狀面顯示脾的大小、形態(tài)及其與鄰近器官的關(guān)系優(yōu)于橫斷面T1WI信號(hào)低于肝T2WI信號(hào)高于肝血管流空無(wú)信號(hào)副脾、多脾及異位脾，信號(hào)強(qiáng)度始終與脾相同脾腫瘤呈稍長(zhǎng)T1長(zhǎng)T2信號(hào)如腫瘤伴出血壞死，則為混雜信號(hào)囊性病變呈圓形長(zhǎng)T1低信號(hào)和長(zhǎng)T2高信號(hào)脾內(nèi)出血的信號(hào)與出血時(shí)間有關(guān)脾內(nèi)鈣化呈黑色低信號(hào)12編輯pptNormalVariants:AccessorySpleen

10%Solitaryormultipleandnomorethan4cmcommonlocationisthesplenichilumShoulddistinguishedfromenlargedLNAxialout-of-phaseimageAccessoryspleenatthehilum13編輯pptPolyspleniaAssociationwithabdominalsitusandcardiovascularanomalies.morecommoninfemalesNumeroussmallsplenicmassesinhypochondriumAxialin-phaseGREimageshowssitusinversuswithmultiplemassesintherightupperquadrant14編輯pptPolyspleniaCoronalGREcineandaxialin-phaseGREimagesAcardiacanomalyintheformofpulmonarystenosisandsmallmassesintheleftupperquadrant15編輯ppt脾外傷易發(fā)生外傷，脾包膜下、脾實(shí)質(zhì)內(nèi)和脾周圍出血據(jù)脾破裂時(shí)間，早發(fā)性脾破裂和遲發(fā)性脾破裂可因感染、腫瘤、血液病等引起自發(fā)性脾破裂急性脾破裂可出現(xiàn)劇烈左上腹疼痛并向背部放射遲發(fā)性脾破裂，癥狀可隱匿數(shù)天至出現(xiàn)大出血16編輯ppt脾外傷平片和透視左上腹脾區(qū)致密塊影；結(jié)腸脾曲因血腫壓迫而下移；左膈抬高，活動(dòng)受限?？砂橛衅渌鈧?，如氣胸、氣腹、肋骨骨折脾動(dòng)脈造影重度：脾破裂，大血管分支破裂中度：脾內(nèi)、外有較多的對(duì)比劑外溢輕度：脾內(nèi)血腫，呈小范圍無(wú)血管區(qū)改變或少量對(duì)比劑外溢17編輯ppt脾外傷CT脾挫裂傷表現(xiàn)為脾內(nèi)不規(guī)則形的低密度區(qū)，還可伴有小點(diǎn)、片狀高密度影脾血腫表現(xiàn)為團(tuán)塊狀高密度影包膜下血腫呈半月形高密度影，隨出血時(shí)間延長(zhǎng)，血腫逐漸變?yōu)榈让芏饶酥恋兔芏仍钇て屏岩娖⒅芑虿⑸细骨环e液（積血）增強(qiáng)掃描有助于顯示較輕的病變18編輯pptTraumaMRIImagingcharacteristicsofsplenichematomasfollowthoseofhemeandhemeproducts,withevolutionlikehematomasinotherpartsofthebodyComparedtosplenicsignalintensity,acutehematomasdemonstrateprolongedT2.Bloodproductsevolveovertimeintomethemoglobin,deoxyhemoglobin,andotherparamagneticdegradationproductswithconcomitantsignalintensitychanges19編輯ppt脾外傷急性脾破裂CT平掃在稍高密度的膈下液體中見脾輪廓斷裂快速注射對(duì)比劑，脾的活組織與周圍的血液分界清楚20編輯ppt脾外傷、破裂根據(jù)脾的形態(tài)，提示脾實(shí)質(zhì)裂傷脾周液體的CT值超過(guò)50HU，表明腹腔內(nèi)存在出血21編輯ppt脾外傷脾血腫被膜下血腫在注射對(duì)比劑后清晰22編輯ppt23編輯ppt24編輯ppt25編輯pptTraumaCoronalT2WIhalf-FourierRAREC-3DVIBEAnacuteorsubacutesubcapsularhematoma26編輯ppt脾腫瘤原發(fā)脾腫瘤少見，惡性以淋巴瘤多，良性以血管瘤多脾惡性淋巴瘤CT可見脾增大，脾內(nèi)單發(fā)或多發(fā)稍低密度灶，邊界不清。增強(qiáng)掃描病灶輕度不規(guī)則強(qiáng)化，與正常脾實(shí)質(zhì)分界清楚脾海綿狀血管瘤CT平掃為邊界清楚的低密度區(qū)，增強(qiáng)早期顯示病灶周邊結(jié)節(jié)狀強(qiáng)化，延遲掃描對(duì)比劑逐漸向中心充填，最后病灶呈等密度脾血管瘤在T2WI呈明顯高信號(hào)，Gd-DTPA增強(qiáng)多明顯強(qiáng)化。淋巴瘤表現(xiàn)為單個(gè)或多個(gè)大小不等的圓形腫塊，邊界不清，在T1WI及T2WI表現(xiàn)為不均勻性混雜信號(hào)27編輯pptInflammationAbscessesbefoundin0.14-0.7%autopsycasesPrevalenceincreasedduetoincreasednumberofimmunosuppressedpatientssuchasAIDSSolitary,

multiple,ormultilocularLowsignalintensityonT1WIandhighsignalintensityonT2WIMinimalperipheralenhancementwhenthecapsuledevelops28編輯pptInflammationSplenicabscessAxialT2WIRE+T1WIfastmultiplanarspoiledGREAIDShyperintenseonT2WIhypointenseonT1WI29編輯pptCandidiasisThemostcommoninfectioninvolvingtheliverandspleeninimmunocompromisedMRIbesuperiortoCTindetectionofmicroabscessessecondarytocandidiasismultiplehypointense,ring-enhancinglesionslessthan1cmonenhancedimages30編輯pptCandidiasisE+3DVIBEimmunocompromisedMultiplesmall,hypointenselesions31編輯pptHistoplasmosisAlthoughseeninpatientswithcompetentimmunesystems,theprevalenceofhistoplasmosisisgreaterinimmunocompromisedpatientsMRIdemonstratestheacuteandsubacutephasesofdiseaseasscatteredhypointenselesionsonbothT1WIandT2WIOldgranulomascanbecalcified,causingcharacteristicsignalintensitychangeswithbloomingartifactsonMRIThisappearanceisbestappreciatedonGRET1WI,especiallythoseobtainedwithalongechotime32編輯pptHistoplasmacapsulatumAxialE+3DVIBET2WIIRScatteredlowsignalintensitylesionsrepresentinfectionofspleen33編輯pptAxialT1WIandT2WIoldcalcifiedsplenichistoplasmomaAlowsignalntensitylesionwithcharacteristic"blooming"34編輯pptSarcoidosisAgranulomatoussystemicdiseaseofunknownetiologythatcaninvolvenumeroussites,infrequentlyinvolvingthespleenNodularsarcoidosisdemonstratelowsignalintensitywithallMRIsequencesLesionsaremostconspicuousonT2WIFSorearlyphaseenhancedimagesSarcoidosislesionsenhanceinaminimalanddelayedpattern35編輯pptSarcoidosismultiplesmall,hypointense,focalspleniclesions,representsarcoidosisnotenhanceonearlyphasebutenhanceondelayedphase

36編輯ppt脾腫瘤非何杰金淋巴瘤平掃見脾大注射對(duì)比劑后可見多發(fā)低密度區(qū)37編輯ppt非何杰金淋巴瘤境界清楚的低密度病灶，注射對(duì)比劑后周邊強(qiáng)化38編輯ppt非何杰金淋巴瘤多發(fā)微小低密度病灶，對(duì)比增強(qiáng)后清楚化學(xué)治療后消失39編輯ppt40編輯ppt41編輯ppt42編輯ppt脾囊腫分為先天性和后天性，真性和假性真性囊腫見于單純性囊腫和多囊脾，假性囊腫見于外傷出血和炎癥之后。脾包蟲囊腫多見于流行區(qū)CT和MRI表現(xiàn)類似于肝腎囊腫寄生蟲性囊腫?？梢娔夷[壁弧形鈣化，外傷性囊腫內(nèi)由于出血和機(jī)化，囊內(nèi)密度高于水43編輯ppt脾囊腫囊腫壁鈣化，考慮為寄生蟲性44編輯pptBenignNeoplasmsorCystsTruespleniccystsareepithelialcelllined,asopposedtopseudocystsIncludeepidermoidandparasiticcystsMRIcharacteristicsfollowthoseofcystsinotherorgansofthebody,withlackoftissuearchitectureandhighwatercontentlongerT1andT2relativetonormalsplenictissuenoenhancementfollowingadministrationofGDDTPAMRIisusefulwhenUSandCTresultsareequivocal45編輯pptSpleniccystAxialE+T1WI3DVIBET2WIhalf-FourierRARETypicalfeatures46編輯ppt脾梗死常見原因是左心系統(tǒng)血栓脫落，脾周圍器官的腫瘤和炎癥引起脾動(dòng)脈血栓并脫落，某些血液病和淤血性脾增大多無(wú)癥狀，少數(shù)可有上腹疼痛脾動(dòng)脈造影見受累動(dòng)脈中斷，并見三角形無(wú)血管區(qū)，尖端指向脾門MRI梗塞區(qū)的信號(hào)強(qiáng)度根據(jù)梗塞時(shí)間長(zhǎng)短不同急性和亞急性梗塞區(qū)在T1WI和T2WI分別為低信號(hào)和高信號(hào)區(qū)慢性期梗塞區(qū)瘢痕和鈣化形成，T1WI和T2WI均為低信號(hào)47編輯ppt脾梗死CT脾內(nèi)三角形低密度影，尖端指向脾門，邊界清楚。增強(qiáng)后無(wú)強(qiáng)化快速注射對(duì)比劑，腫大的脾內(nèi)可見局限性低密度區(qū)，脾被膜輕度凹陷48編輯ppt脾梗死脾臟完全梗死，周圍脾實(shí)質(zhì)接受被膜血管的血供49編輯pptSplenicInfarctionSeeninthesettingofarterialembolisuchasinsicklecellanemia,Gaucherdisease,hematologicmalignancies,cardiacemboli,torsion,collagenvasculardisease,andportalhypertensionPeripheralwedge-shapeddefectsthatexhibitdecreasedsignalintensityonbothT1WIandT2WIanddonotenhanceafterintravenouscontrastmaterialadministration50編輯pptSplenicInfarctionAxialE+3DVIBEnonenhancingwedge-shapedareaofinfarction51編輯pptSplenicarteryaneurysmsSecondarytomultiplecausessuchasmedialdegenerationwithsuperimposedatherosclerosis,congenitalcauses,mycoticcauses,portalhypertension,fibromusculardysplasia,andpseudoaneurysmsfromtraumaandpancreatitisMRIallowseffectivediagnosisandcharacterizationoftheselesions3DGREsequencessuchasVIBEordedicated3DMRangiographicsequencesarethebestforevaluatingtheselesions52編輯pptSplenicarteryaneurysmsE+3DGREVIBEAneurysmaldilatationofdistalendofsplenicartery53編輯pptSplenicveinthrombosisMostcommonlysecondarytopancreatitisAtleast20%withchronicpancreatitisCompressionandfibrosiscausedbypancreatitisErosionofapseudocystintothesplenicveinMayresultingastricvaricesandattimeseitheresophagealorcolonicvaricesanintraluminalfillingdefectafteriv.contrastE+MRAhasthepotentialtoreplaceia.DSAasthestandardmethodofassessingtheportalvenousanatomy54編輯pptSplenicveinthrombosisAxialvenousphaseE+3DGREVIBEThrombusfillingthesplenicveinAppearsasanareaofsignalvoid55編輯pptArteriovenousmalformationsCanoccuranywhereinthehumanbodybutrarelyoccurinthespleenAmachinery-typebruitintheupperleftabdominalquadrantrepresentsanimportantandsimplediagnosticsymptomfoundatclinicalexaminationduringauscultationMRimagingcandemonstratearteriovenousmalformationsasmultiplesignalvoidswithallnonenhancedpulsesequencesArteriovenousmalformationsdemonstrateserpentineenhancementafterintravenousinjectionofgadoliniumcontrastmaterial56編輯pptArteriovenousmalformationsAxialT2-weightedinversion-recoveryandcontrast-enhanced3DVIBEimagesAspleniclesionthatappearsasanareaofsignalvoidThelesiondemonstratesserpentineenhancementontheenhancedimageandrepresentsanarteriovenousmalformation57編輯pptHematologicDisorders

SickleCellDiseaseCommonintheblackpopulationwithaprevalenceof0.2%(homozygousform)and8%–10%(heterozygousform)ThespleenistheorganmostcommonlyinvolvedbysicklecelldiseaseAppearsasanearlysignalvoidareaduetoirondepositionfrombloodtransfusionAutosplenectomyisoftenfoundinpatientswithhomozygoussicklecelldisease58編輯pptSickleCellDiseaseT2WIhalf-FourierRAREDecreasedsignalintensityisduetorepeatedbloodtransfusion59編輯pptSickleCellDiseaseAxialE+T1WIGREAverysmallspleenisindicativeofautosplenectomy60編輯pptExtramedullaryhematopoiesisAcompensatoryresponsetodeficientbonemarrowcellspredominantlyaffectsthespleenandliverAlthoughusuallyshowsdiffuseinfiltrationmicroscopically,maybefocalmasslikeinvolvementofliverandspleenSignalintensitydependsonevolutionofhematopoiesisActivelesionsshowintermediatesignalintensityonT1WI,highsignalintensityonT2WI,andsomeenhancementOlderlesionsshowlowsignalintensityonT1WIandT2WIandmaynotshowanyenhancementusuallyexhibitreducedsignalintensityonin-phaseT1WIGREcomparedwiththatonopposed-phaseimagesowingtothepresenceofiron61編輯pptExtramedullaryhematopoiesisThelesionhasreducedsignalintensityonthein-phaseimagecomparedwiththatontheout-of-phaseimageThisdifferenceissecondarytoirondeposition62編輯pptHemangiomaThemostcommonprimarybenignneoplasmofthespleenComposedofendothelium-linedvascularchannelsfilledwithbloodMostarehypointensetothespleenonT1WIandhyperintenseonT2WIEarlynodularcentripetalenhancementanduniformenhancementatdelayedimaging63編輯pptSplenichemangiomaAxialT2WIFSEandE+3DVIBETypicalMRIfeatures64編輯pptDiffusehemangiomatosisArarebenignvascularconditionoccurringasamanifestationofsystemicangiomatosisAssociationswithKlippel-Trénaunay-Weber,Turner,Kasabach-Merritt–like,andBeckwith-Wiedemannsyndromeslesscommonly,confinedtothespleenSometimesaccompaniedbyseveredisturbanceofbloodcoagulation65編輯pptAxialE+3DVIBEandT2WIofaKlippel-Trénaunay-WebersyndromeDiffuseangiomatosisofthespleenandchestwall66編輯pptHamartomasBenignasymptomaticlesions,usuallysingle,composedofamixtureofnormalsplenicstructuressuchaswhiteandredpulpCommonlyassociatedwithtuberoussclerosisHeterogeneouslyhyperintenserelativetothespleenonT2WIanddemonstratediffuseenhancementonearlypostcontrastimagesandmoreuniformenhancementondelayedimages67編輯pptHamartomasLesionwithhighsignalintensityonT2WI,lowsignalintensityonT1WI,andmoreuniformenhancementonthedelayedimage68編輯pptSplenicSarcomaPrimarysplenicangiosarcomasareextremelyraretumorswithaverypoorprognosis.highlyaggressiveandmanifestwithwide-spreadmetastaticdiseaseorsplenicruptureLowsignalintensityonT1WIandheterogeneoushighsignalintensityonT2WIHeterogeneousenhancementwithmultiplehyperintensenodularfociandhypointenseregionsMRIseemstobemorepreciseintheoverallassessmentandstagingofthistypeoftumorandisofparticularvaluefortimelydiagnosisofthisrapidlyfataldisease69編輯pptAngiosarcomaE+3DVIBET2WIhalf-FourierRARELowonT1WIHighonT2WIHeterogeneousenhancement70編輯pptLymphomaThecommonestmalignanttumorofthespleenItisimportanttodetectsplenicinvolvementbecauseitcanalterthemanagementLymphomatousdepositshaveT1andT2similartothoseofnormalsplenicparenchymaEnhancedsequencesaremoresensitivefortheevaluationofspleniclymphomaDiffuseinvolvementmaybeseenaslargeirregularlyenhancingregionsMultifocaldiseaseisalsocommonandcanbeseenasmultiplefocallesionsthatarehypointenserelativetotheuniformlyorarciformenhancingspleen71編輯pptLymphomaE+3DGREVIBEMultifocalinvolvementofthespleenbymultiplehypointenselymphomatouslesions72編輯pptMetastasesRelativelyuncommonUsuallyinwidespreaddisseminatedmalignanciesIsolatedsplenicmetastasesalsorecognizedTypicallyashyperintensemassesonT2WIandhypo-toisointensemassesonT1WIThedegreeandcharacteristicsofenhancementdependonthenatureandtypeoftheunderlyingprimaryneoplasm73編輯pptMetastasesT2-WIhalf-FourierRAREApatientwhounderwentleftnephrectomyforrenalcellcarcinomashowshyperintensesplenicmetastases74編輯pptSplenicenlargementCausedbyvariousdiseasesLymphomaMalariaLeukemiaportalhypertensionmetabolicdiseases(eg,Gaucherdisease)75編輯pptP