《脾脏影像诊断学》PPT课件

1,脾脏影像诊断学,2,脾脏影像检查技术,X线：价值有限，血管造影USCT：为更清楚显示小病变，可应用5mm的层厚和层距平扫发现可疑应增强,3,MRImagingTechnique,CoronalT2WIhalf-Fourierrapidacquisitionwithrelaxationenhancement(RARE)AxialFSET2WIorlongechotimeinversion-recoveryimagingperformedduringabreathholdAxialGRET1WIchemicalshiftin-phaseandout-of-phaseimagingperformedduringabreathholdAxial3DGREbreath-holdsequencesuchasvolumetricinterpolatedbreath-holdexamination(VIBE)withpre-contrastanddynamicenhanced,4,MRImagingTechnique,LowerthanliveronT1WIandhigheronT2WIImagesobtainedimmediatelyafterenhancementusuallydemonstratedifferentcirculationsasregionsofalternatinghighandlowsignalintensity,resultinginaserpentineorarciformpatternBecomeshomogeneousapproximately6090saftercontrastmaterialadministration,5,Anatomy,Thelargestductlessglandandthelargestsinglelymphaticorganinthebodymesodermalinorigintothecirculatorysystemasthelymphnodesfunctionsincludeimmunologicsurveillance,redbloodcellbreakdown,andspleniccontractionforbloodvolumeaugmentationduringhemorrhageAwiderangeofpathologycanaffectthespleen,6,Anatomy,Anintraperitonealorganwithasmoothserosalsurfaceandattachedtotheretroperitoneumbyfattyligamentssurfaces:diaphragmatic(phrenic)andvisceralVisceralsurfaceisdividedintoananteriororgastricridgeandaposteriororrenalportionSplenicarteryandveinemergefromthesplenichilumintheformofsixormorebranches;thesplenicarteryisremarkableforitslargesizeandtortuosity.slightlysuperiortothevein,7,MicroscopicAnatomy,dividedintotwocompartments,theredandwhitepulps,separatedbythemarginalzoneThewhitepulpismadeupofTandBlymphocytesandlocatedcentrallyTheredpulpiscomposedofrichplexusesoftortuousvenoussinuses,8,脾的大小,新月形或内缘凹陷的半月形，密度均匀略低于肝前后径710宽径46上下径1115,9,动脉期强化不均匀静脉期和实质期密度逐渐均匀一致,10,20,60,30,10,Arciformnormalenhancementpattern,Axial3DGREVIBEImmediatelyafteradministrationofcontrastmaterialArciformnormalenhancementpattern,11,脾的异常CT表现,平扫脾增大数目：多、副、无密度异常低密度：肿瘤、脓肿、囊肿、梗死、挫伤高密度：外伤血肿、错构瘤、钙化,对比增强病灶强化：血管瘤、淋巴瘤、转移瘤环状强化：脓肿病灶无强化：囊肿、梗死,12,MRI影像分析,横断面大小、形态与CT相似冠状面显示脾的大小、形态及其与邻近器官的关系优于横断面T1WI信号低于肝T2WI信号高于肝血管流空无信号,副脾、多脾及异位脾，信号强度始终与脾相同脾肿瘤呈稍长T1长T2信号如肿瘤伴出血坏死，则为混杂信号囊性病变呈圆形长T1低信号和长T2高信号脾内出血的信号与出血时间有关脾内钙化呈黑色低信号,13,NormalVariants:AccessorySpleen,10%Solitaryormultipleandnomorethan4cmcommonlocationisthesplenichilumShoulddistinguishedfromenlargedLNAxialout-of-phaseimageAccessoryspleenatthehilum,14,Polysplenia,Associationwithabdominalsitusandcardiovascularanomalies.morecommoninfemalesNumeroussmallsplenicmassesinhypochondriumAxialin-phaseGREimageshowssitusinversuswithmultiplemassesintherightupperquadrant,15,Polysplenia,CoronalGREcineandaxialin-phaseGREimagesAcardiacanomalyintheformofpulmonarystenosisandsmallmassesintheleftupperquadrant,16,脾外伤,易发生外伤，脾包膜下、脾实质内和脾周围出血据脾破裂时间，早发性脾破裂和迟发性脾破裂可因感染、肿瘤、血液病等引起自发性脾破裂急性脾破裂可出现剧烈左上腹疼痛并向背部放射迟发性脾破裂，症状可隐匿数天至出现大出血,17,脾外伤,平片和透视左上腹脾区致密块影；结肠脾曲因血肿压迫而下移；左膈抬高，活动受限。可伴有其他外伤，如气胸、气腹、肋骨骨折脾动脉造影重度：脾破裂，大血管分支破裂中度：脾内、外有较多的对比剂外溢轻度：脾内血肿，呈小范围无血管区改变或少量对比剂外溢,18,脾外伤CT,脾挫裂伤表现为脾内不规则形的低密度区，还可伴有小点、片状高密度影脾血肿表现为团块状高密度影包膜下血肿呈半月形高密度影，随出血时间延长，血肿逐渐变为等密度乃至低密度灶脾包膜破裂见脾周或并上腹腔积液（积血）增强扫描有助于显示较轻的病变,19,TraumaMRI,Imagingcharacteristicsofsplenichematomasfollowthoseofhemeandhemeproducts,withevolutionlikehematomasinotherpartsofthebodyComparedtosplenicsignalintensity,acutehematomasdemonstrateprolongedT2.Bloodproductsevolveovertimeintomethemoglobin,deoxyhemoglobin,andotherparamagneticdegradationproductswithconcomitantsignalintensitychanges,20,脾外伤,急性脾破裂CT平扫在稍高密度的膈下液体中见脾轮廓断裂快速注射对比剂，脾的活组织与周围的血液分界清楚,21,脾外伤、破裂,根据脾的形态，提示脾实质裂伤脾周液体的CT值超过50HU，表明腹腔内存在出血,22,脾外伤,脾血肿被膜下血肿在注射对比剂后清晰,23,24,25,26,Trauma,CoronalT2WIhalf-FourierRAREC-3DVIBEAnacuteorsubacutesubcapsularhematoma,27,脾肿瘤,原发脾肿瘤少见，恶性以淋巴瘤多，良性以血管瘤多脾恶性淋巴瘤CT可见脾增大，脾内单发或多发稍低密度灶，边界不清。增强扫描病灶轻度不规则强化，与正常脾实质分界清楚脾海绵状血管瘤CT平扫为边界清楚的低密度区，增强早期显示病灶周边结节状强化，延迟扫描对比剂逐渐向中心充填，最后病灶呈等密度脾血管瘤在T2WI呈明显高信号，Gd-DTPA增强多明显强化。淋巴瘤表现为单个或多个大小不等的圆形肿块，边界不清，在T1WI及T2WI表现为不均匀性混杂信号,28,Inflammation,Abscessesbefoundin0.14-0.7%autopsycasesPrevalenceincreasedduetoincreasednumberofimmunosuppressedpatientssuchasAIDSSolitary,multiple,ormultilocularLowsignalintensityonT1WIandhighsignalintensityonT2WIMinimalperipheralenhancementwhenthecapsuledevelops,29,Inflammation,SplenicabscessAxialT2WIRE+T1WIfastmultiplanarspoiledGREAIDShyperintenseonT2WIhypointenseonT1WI,30,Candidiasis,ThemostcommoninfectioninvolvingtheliverandspleeninimmunocompromisedMRIbesuperiortoCTindetectionofmicroabscessessecondarytocandidiasismultiplehypointense,ring-enhancinglesionslessthan1cmonenhancedimages,31,Candidiasis,E+3DVIBEimmunocompromisedMultiplesmall,hypointenselesions,32,Histoplasmosis,Althoughseeninpatientswithcompetentimmunesystems,theprevalenceofhistoplasmosisisgreaterinimmunocompromisedpatientsMRIdemonstratestheacuteandsubacutephasesofdiseaseasscatteredhypointenselesionsonbothT1WIandT2WIOldgranulomascanbecalcified,causingcharacteristicsignalintensitychangeswithbloomingartifactsonMRIThisappearanceisbestappreciatedonGRET1WI,especiallythoseobtainedwithalongechotime,33,Histoplasmacapsulatum,AxialE+3DVIBET2WIIRScatteredlowsignalintensitylesionsrepresentinfectionofspleen,34,AxialT1WIandT2WIoldcalcifiedsplenichistoplasmomaAlowsignalntensitylesionwithcharacteristicblooming,35,Sarcoidosis,Agranulomatoussystemicdiseaseofunknownetiologythatcaninvolvenumeroussites,infrequentlyinvolvingthespleenNodularsarcoidosisdemonstratelowsignalintensitywithallMRIsequencesLesionsaremostconspicuousonT2WIFSorearlyphaseenhancedimagesSarcoidosislesionsenhanceinaminimalanddelayedpattern,36,Sarcoidosis,multiplesmall,hypointense,focalspleniclesions,representsarcoidosisnotenhanceonearlyphasebutenhanceondelayedphase,37,脾肿瘤,非何杰金淋巴瘤平扫见脾大注射对比剂后可见多发低密度区,38,非何杰金淋巴瘤,境界清楚的低密度病灶，注射对比剂后周边强化,39,非何杰金淋巴瘤,多发微小低密度病灶，对比增强后清楚化学治疗后消失,40,41,42,43,脾囊肿,分为先天性和后天性，真性和假性真性囊肿见于单纯性囊肿和多囊脾，假性囊肿见于外伤出血和炎症之后。脾包虫囊肿多见于流行区CT和MRI表现类似于肝肾囊肿寄生虫性囊肿常可见囊肿壁弧形钙化，外伤性囊肿内由于出血和机化，囊内密度高于水,44,脾囊肿,囊肿壁钙化，考虑为寄生虫性,45,BenignNeoplasmsorCysts,Truespleniccystsareepithelialcelllined,asopposedtopseudocystsIncludeepidermoidandparasiticcystsMRIcharacteristicsfollowthoseofcystsinotherorgansofthebody,withlackoftissuearchitectureandhighwatercontentlongerT1andT2relativetonormalsplenictissuenoenhancementfollowingadministrationofGDDTPAMRIisusefulwhenUSandCTresultsareequivocal,46,Spleniccyst,AxialE+T1WI3DVIBET2WIhalf-FourierRARETypicalfeatures,47,脾梗死,常见原因是左心系统血栓脱落，脾周围器官的肿瘤和炎症引起脾动脉血栓并脱落，某些血液病和淤血性脾增大多无症状，少数可有上腹疼痛脾动脉造影见受累动脉中断，并见三角形无血管区，尖端指向脾门MRI梗塞区的信号强度根据梗塞时间长短不同急性和亚急性梗塞区在T1WI和T2WI分别为低信号和高信号区慢性期梗塞区瘢痕和钙化形成，T1WI和T2WI均为低信号,48,脾梗死,CT脾内三角形低密度影，尖端指向脾门，边界清楚。增强后无强化快速注射对比剂，肿大的脾内可见局限性低密度区，脾被膜轻度凹陷,49,脾梗死,脾脏完全梗死，周围脾实质接受被膜血管的血供,50,SplenicInfarction,Seeninthesettingofarterialembolisuchasinsicklecellanemia,Gaucherdisease,hematologicmalignancies,cardiacemboli,torsion,collagenvasculardisease,andportalhypertensionPeripheralwedge-shapeddefectsthatexhibitdecreasedsignalintensityonbothT1WIandT2WIanddonotenhanceafterintravenouscontrastmaterialadministration,51,SplenicInfarction,AxialE+3DVIBEnonenhancingwedge-shapedareaofinfarction,52,Splenicarteryaneurysms,Secondarytomultiplecausessuchasmedialdegenerationwithsuperimposedatherosclerosis,congenitalcauses,mycoticcauses,portalhypertension,fibromusculardysplasia,andpseudoaneurysmsfromtraumaandpancreatitisMRIallowseffectivediagnosisandcharacterizationoftheselesions3DGREsequencessuchasVIBEordedicated3DMRangiographicsequencesarethebestforevaluatingtheselesions,53,Splenicarteryaneurysms,E+3DGREVIBEAneurysmaldilatationofdistalendofsplenicartery,54,Splenicveinthrombosis,MostcommonlysecondarytopancreatitisAtleast20%withchronicpancreatitisCompressionandfibrosiscausedbypancreatitisErosionofapseudocystintothesplenicveinMayresultingastricvaricesandattimeseitheresophagealorcolonicvaricesanintraluminalfillingdefectafteriv.contrastE+MRAhasthepotentialtoreplaceia.DSAasthestandardmethodofassessingtheportalvenousanatomy,55,Splenicveinthrombosis,AxialvenousphaseE+3DGREVIBEThrombusfillingthesplenicveinAppearsasanareaofsignalvoid,56,Arteriovenousmalformations,CanoccuranywhereinthehumanbodybutrarelyoccurinthespleenAmachinery-typebruitintheupperleftabdominalquadrantrepresentsanimportantandsimplediagnosticsymptomfoundatclinicalexaminationduringauscultationMRimagingcandemonstratearteriovenousmalformationsasmultiplesignalvoidswithallnonenhancedpulsesequencesArteriovenousmalformationsdemonstrateserpentineenhancementafterintravenousinjectionofgadoliniumcontrastmaterial,57,Arteriovenousmalformations,AxialT2-weightedinversion-recoveryandcontrast-enhanced3DVIBEimagesAspleniclesionthatappearsasanareaofsignalvoidThelesiondemonstratesserpentineenhancementontheenhancedimageandrepresentsanarteriovenousmalformation,58,HematologicDisordersSickleCellDisease,Commonintheblackpopulationwithaprevalenceof0.2%(homozygousform)and8%10%(heterozygousform)ThespleenistheorganmostcommonlyinvolvedbysicklecelldiseaseAppearsasanearlysignalvoidareaduetoirondepositionfrombloodtransfusionAutosplenectomyisoftenfoundinpatientswithhomozygoussicklecelldisease,59,SickleCellDisease,T2WIhalf-FourierRAREDecreasedsignalintensityisduetorepeatedbloodtransfusion,60,SickleCellDisease,AxialE+T1WIGREAverysmallspleenisindicativeofautosplenectomy,61,Extramedullaryhematopoiesis,AcompensatoryresponsetodeficientbonemarrowcellspredominantlyaffectsthespleenandliverAlthoughusuallyshowsdiffuseinfiltrationmicroscopically,maybefocalmasslikeinvolvementofliverandspleenSignalintensitydependsonevolutionofhematopoiesisActivelesionsshowintermediatesignalintensityonT1WI,highsignalintensityonT2WI,andsomeenhancementOlderlesionsshowlowsignalintensityonT1WIandT2WIandmaynotshowanyenhancementusuallyexhibitreducedsignalintensityonin-phaseT1WIGREcomparedwiththatonopposed-phaseimagesowingtothepresenceofiron,62,Extramedullaryhematopoiesis,Thelesionhasreducedsignalintensityonthein-phaseimagecomparedwiththatontheout-of-phaseimageThisdifferenceissecondarytoirondeposition,63,Hemangioma,ThemostcommonprimarybenignneoplasmofthespleenComposedofendothelium-linedvascularchannelsfilledwithbloodMostarehypointensetothespleenonT1WIandhyperintenseonT2WIEarlynodularcentripetalenhancementanduniformenhancementatdelayedimaging,64,Splenichemangioma,AxialT2WIFSEandE+3DVIBETypicalMRIfeatures,65,Diffusehemangiomatosis,ArarebenignvascularconditionoccurringasamanifestationofsystemicangiomatosisAssociationswithKlippel-Trnaunay-Weber,Turner,Kasabach-Merrittlike,andBeckwith-Wiedemannsyndromeslesscommonly,confinedtothespleenSometimesaccompaniedbyseveredisturbanceofbloodcoagulation,66,AxialE+3DVIBEandT2WIofaKlippel-Trnaunay-WebersyndromeDiffuseangiomatosisofthespleenandchestwall,67,Hamartomas,Benignasymptomaticlesions,usuallysingle,composedofamixtureofnormalsplenicstructuressuchaswhiteandredpulpCommonlyassociatedwithtuberoussclerosisHeterogeneouslyhyperintenserelativetothespleenonT2WIanddemonstratediffuseenhancementonearlypostcontrastimagesandmoreuniformenhancementondelayedimages,68,Hamartomas,LesionwithhighsignalintensityonT2WI,lowsignalintensityonT1WI,andmoreuniformenhancementonthedelayedimage,69,SplenicSarcoma,Primarysplenicangiosarcomasareextremelyraretumorswithaverypoorprognosis.highlyaggressiveandmanifestwithwide-spreadmetastaticdiseaseorsplenicruptureLowsignalintensityonT1WIandheterogeneoushighsignalintensityonT2WIHeterogeneousenhancementwithmultiplehyperintensenodularfociandhypointenseregionsMRIseemstobemorepreciseintheoverallassessmentandstagingofthistypeoftumorandisofparticularvaluefortimelydiagnosisofthisrapidlyfataldisease,70,Angiosarcoma,E+3DVIBET2WIhalf-FourierRARELowonT1WIHighonT2WIHeterogeneousenhancement,71,Lymphoma,ThecommonestmalignanttumorofthespleenItisimportanttodetectsplenicinvolvementbecauseitcanalterthemanagementLymphomatousdepositshaveT1andT2similartothoseofnormalsplenicparenchymaEnhancedsequencesaremoresensitivefortheevaluationofspleniclymphomaDiffuseinvolvementmaybeseenaslargeirregularlyenhancingregionsMultifocaldiseaseisalsocommonandcanbeseenasmultiplefocallesionsthatarehypointenserelativetotheuniformlyorarciformenhancingspleen,72,Lymphoma,E+3DGREVIBEMultifocalinvolvementofthespleenbymultiplehypointenselymphomatouslesions,73,Metastases,RelativelyuncommonUsuallyinwidespreaddisseminatedmalignanciesIsolatedsplenicmetastasesalsorecognizedTypicallyashyperintensemassesonT2WIandhypo-toisointensemassesonT1WIThedegreeandcharacteristicsofenhancementdependonthenatureandtypeoftheunderlyingprimaryneoplasm,74,Metastases,T2-WIhalf-FourierRAREApatientwhounderwentleftnephrectomyforrenalcellcarcinomashowshyperintensesplenicmetastases,75,Splenicenlargement,CausedbyvariousdiseasesLymphomaMalariaLeukemiaportalhypertensionmetabolicdiseases(eg,Gaucherdise