Brain-Tumor-Systematic教学讲解课件

BrainTumor-SystematicApproach

byRobinSmithuisandWalterMontanera

河南省人民医院放射科

高明译讲BrainTumor-SystematicAppro1IntroductionIncidenceofCNStumorsAgedistributionTumorspreadIntra-versusExtraaxialMidlinecrossingMultifocaldiseaseCorticalbasedtumorsCTandMRCharacteristicsBrain-Tumor---Systematic教学讲解课件2Fat-Calcification-CystHighonT1LowonT2DiffusionweightedimagingPerfusionImagingEnhancementDifferentialdiagnosis

forspecificFat-Calcification-Cyst3Brain-Tumor---Systematic教学讲解课件4Brain-Tumor---Systematic教学讲解课件5Brain-Tumor---Systematic教学讲解课件6Brain-Tumor---Systematic教学讲解课件7Brain-Tumor---Systematic教学讲解课件8Brain-Tumor---Systematic教学讲解课件9Brain-Tumor---Systematic教学讲解课件10Schwannomalocatedinthecerebellopontineangle(CPA)

withtypicalsignsofanextraaxialtumorSchwannomalocatedinthecere11Meningiomawithabroadduralbaseandaduraltail，hyperostosisintheadjacentbone，enhanceshomogeneously，noblood-brain-barrierMeningiomawithabroaddural12Melanomametastasiswithgraymatterontheanteromedialsideofthelesion(redarrow)，intra-axial.

Melanomametastasiswithgray13Ependymomawithextensiontothecerebellopontineangle(bluearrow)andintotheforamenmagnum

(redarrow)ortothecisternamagnaEpendymomawithextensiontot14Toassesstheextentofatumor.

Anextra-axialtumorintheregionoftheleftcavernoussinuswithhomogeneousenhancementandabroadduraltail.

Thisistypicalforameningioma.Toassesstheextentofatumo15Actualextentofthistumorisgreaterthanexpected.

Thetumorissituatedinthepterygopalatinefossaandextendsintotheorbit.

Italsospreadsanteriorlyintothemiddlecranialfossa.Actualextentofthistumoris16Considerationfortheeffectonthesurroundingstructures.Primarybraintumorsarederivedfrombraincellsandoftenhavelessmasseffectfortheirsizethanyouwouldexpect,duetotheirinfiltrativegrowth.Thereisnoenhancementsothiswouldprobablybealow-gradeastrocytomaConsiderationfortheeffecto17Brain-Tumor---Systematic教学讲解课件18Theabilityoftumorstocrossthemidline

Glioblastomamultiforme(GBM)frequentlycrossesthemidlinebyinfiltratingthewhitemattertractsofthecorpuscallosum.

RadiationnecrosiscanlooklikerecurrentGBMandcansometimescrossthemidline.

Meningiomaisanextra-axialtumorandcanspreadalongthemeningestothecontralateralside.

Lymphomaisusuallylocatednearthemidline.

Epidermoidcystscancrossthemidlineviathesubarachnoidspace.

MScanalsopresentasamasslesioninthecorpuscallosum.Theabilityoftumorstocross19Left:MetastasesRight:MultiplemeningiomasandaschwannomainapatientwithNeurofibromatosisIILeft:Metastases20

Multifocaldisease:

Metastaticdisease

lymphomas

MulticentricGlioblastomamultiforme(GBM)

Gliomatosiscerebri

Seedingmetastases:Medulloblastomas,Ependymomas,GBMsandoligodendrogliomas

Phacomatoses:

NeurofibromatosisI:opticgliomasandastrocytomas

NeurofibromatosisII:meningiomas,ependymomas,choroidplexuspapillomas

TuberousSclerosis:subependymaltubers,intraventriculargiantcellastrocytomas,ependymomas

vonHippelLindau:hemangioblastomas

Non-tumorousdiseaseslikesmallvesseldisease,infections(septicemboli,abscesses)ordemyelinatingdiseaseslikeMS

Multifocaldisease:

Metast21Corticalbasedtumors

Mostintra-axialtumorsarelocatedinthewhitematter.

Sometumors,however,spreadtoorarelocatedinthegraymatter.

Thesecorticalbasedtumorsincludesoligodendroglioma,

gangliogliomaandDysembryoplastic

NeuroepithialTumor(DNET).

Thedifferentialdiagnosisincludesnon-tumorouslesionslikecerebritis,herpessimplexencephalitis,infarctionandpost-ictalchanges.Corticalbasedtumors

Mostint22A45-year-oldfemalewithastableseizuredisorderfor15years.

Thisisaganglioglioma.

ThedifferentialdiagnosisincludesDNETandpilocyticastrocytoma.

A45-year-oldfemalewithast23A10-year-oldmalewithsecondaryepilepsy.

ThisisaDysembryoplastic

NeuroepithialTumor(DNET)..

Brain-Tumor---Systematic教学讲解课件2452-year-oldfemalewhocomplainedofheadacheandneckpainforoneyearwith

arecentonsetoftonic-clonicseizures.Thisisaninfiltratingtumorwhichextendsallthewaytothecortex,

withlimitedmasseffectonsurroundingstructuresandcalcifications.Themostlikelydiagnosisisoligodendroglioma.52-year-oldfemalewhocomplai25Fat-Calcification-CystAruptureddermoidcystwiththeclassicalfindings.

Chemicalshiftartefactindicatesthepresenceoffat,seenonlyinthefrequencyencodingdirection.Fatwithinatumorisseeninlipomas,

dermoid

cystsandteratomas.Sometumorslikelymphoma,colloidcystandPNET-MB(medulloblastoma)canhaveahighdensityonCT.Fat-Calcification-Cyst26Acalcifiedmassinthesuprasellarregion,causingobstructivehydrocephalus.ThislocationandthecalcificationaretypicalforaCraniopharyngioma.

Apineocytomaitselfdoesnotcalcify,butinsteadit'explodes'thecalcificationsofthepinealgland.Acalcifiedmassinthesupras27Thecalcificationandtheextensionofthetumortothecortexareverytypicalforanoligodendroglioma.

Anastrocytomashouldbeinthedifferential.Thecalcificationandtheexte28Apatientwithprogressivevisualloss.OnthecoronalandsagittalT1WIthereisalargemasscenteredaroundthesellawithabroadduralbase.

Thereisextensionintothesella.

Thisisacalcifiedmeningioma.

Apatientwithprogressivevis29

ManycysticlesionscansimulateaCNStumor.Theseincludeepidermoid,dermoid,arachnoid,neuroentericandneuroglialcysts,enlargedperivascularspacesofVirchowRobin.

Inordertodeterminewhetheralesionisacystorcysticmass，lookforthefollowingcharacteristics:MorphologyFluid/fluidlevel

ContentusuallyisointensetoCSFonT1,T2andFLAIRDWI:restricteddiffusionAnarachnoidcystisisointensetoCSFonallsequences.

Tumornecrosismaysometimeslooklikeacyst,butitisnevercompletelyisointensetoCSF.CysticversusSolid

Manycysticlesionscansimul30Ontheleftacraniopharyngiomawithanenhancingrimsurroundingthecysticcomponent.

InthemiddleaneuroentericcystwiththecontentsofwhichhavethesamesignalintensityasCSF.

Ontherightaglioblastomamultiforme(GBM)withacentralcysticcomponent.

TheenhancementinGBMisusuallymoreirregular.Ontheleftacraniopharyngiom31MosttumorshavealoworintermediatesignalintensityonT1WI.

Exceptionstothisrulecanindicateaspecifictypeoftumor.

CalcificationsaremostlydarkonT1WI,butdependingonthematrixofthecalcificationstheycansometimesbebrightonT1.

EspeciallyongradientechoimagesslowflowcanbeseenasbrightsignalonT1WIandshouldnotbeconfusedwithenhancement.

Ifyouonlydoanenhancedscan,rememberthathighsignalisnotalwaysenhancement.HighonT1Mosttumorshavealoworinte32Brain-Tumor---Systematic教学讲解课件33SometumorswithhighsignalintensitiesonT1WI.

Onthefarleftimagesofapatientwhopresentedwithapoplexy.

Thehighsignalisduetohemorrhageinapituitarymacroadenoma.

Thepatientinthemiddlehasaglioblastomamultiforme,whichcausedahemorrhageinthespleniumofthecorpuscallosum.

Ontherightisapatientwithametastasisofamelanoma.

Thehighsignalintensityisduetothemelanincontent.Sometumorswithhighsignali34MosttumorswillbebrightonT2WIduetoahighwatercontent.

Whentumorshavealowwatercontenttheyareverydenseandhypercellularandthecellshaveahighnuclear-cytoplasmasmicratio.ThesetumorswillbedarkonT2WI.TheclassicexamplesareCNSlymphomaandPNET(alsohyperdenseonCT).

CalcificationsaremostlydarkonT2WI.

Paramagneticeffectscauseasignaldropandareseenintumorsthatcontainhemosiderin.

ProteinaceousmaterialcanbedarkonT2dependingonthecontentoftheproteinitself.

Aclassicexampleofthisisthecolloidcyst.

FlowvoidsarealsodarkonT2andindicatethepresenceofvesselsorflowwithinalesion.

Thisisseenintumorsthatcontainalotofvesselslikehemangioblastomas,butalsoinnon-tumorouslesionslikevascularmalformations.LowonT2Mosttumorswillbebrighton35Brain-Tumor---Systematic教学讲解课件36Melanomawithmelanin.GBMsometimeswithahighnuclear-cytoplasmicratio.MostGBM'sarehyperintenseonT2WI.PNETtypicallyhasahighnuclear-cytoplasmicratio，whichmostlylocatedintheregionofthe4thventricle,anotherlesscommonlocationisintheregionofthepinealgland.Mucinousmetastasesoftenwithcalcifications.Meningiomas：iso-SI.

HighSIonT2WIiftheycontainalotofwater.

LowSIonT2WIiftheyareverydenseandhypercellularorwhentheycontaincalcifications.Melanomawithmelanin.37HighintensityonDWIindicatesrestrictionoftheabilityofwaterprotonstodiffuseextracellularly.

Restricteddiffusionisseeninabscesses,epidermoidcystsandacuteinfarction(duetocytotoxicedema).Incerebralabscessesthediffusionisprobablyrestrictedduetotheviscosityofpus,resultinginahighsignalonDWI.

Inmosttumorsthereisnorestricteddiffusion-eveninnecroticorcysticcomponents.

Thisresultsinanormal,lowsignalonDWI.DiffusionweightedimagingHighintensityonDWIindicate38Brain-Tumor---Systematic教学讲解课件39PerfusionimagingcanplayanimportantroleindeterminingthemalignancygradeofaCNStumor.

Perfusiondependsonthevascularityofatumorandisnotdependentonthebreakdownoftheblood-brainbarrier.

Theamountofperfusionshowsabettercorrelationwiththegradeofmalignancyofatumorthantheamountofcontrastenhancement.PerfusionImagingPerfusionImaging40Brain-Tumor---Systematic教学讲解课件41Bloodbrainbarrier

Thebrainhasauniquetriplelayeredblood-brainbarrier(BBB)withtightendothelialjunctionsinordertomaintainaconsistentinternalmilieu.

Contrastwillnotleakintothebrainunlessthisbarrierisdamaged.

EnhancementisseenwhenaCNStumordestroystheBBB.Extra-axialtumorssuchasmeningiomasandschwannomasarenotderivedfrombraincellsanddonothaveaBBB.

Thereforetheywillenhance.

Thereisalsonoblood-brainbarrierinthepituitary,pinealandchoroidplexusregions.Somenon-tumorallesionsenhancebecausetheycanalsobreakdowntheBBBandmaysimulateabraintumor.

Theselesionsincludelikeinfections,demyelinatingdiseases(MS)andinfarctions.EnhancementBloodbrainbarrier

Thebrain42Brain-Tumor---Systematic教学讲解课件43Contrastenhancementcannotvisualizethefullextentofatumorincasesofinfiltratingtumors,likegliomas.

Thereasonforthisisthattumorcellsblendwiththenormalbrainparenchymawherethebloodbrainbarrierisstillintact.

TumorcellscanbefoundbeyondtheenhancingmarginsofthetumorandbeyondanyMRsignalalteration-evenbeyondtheareaofedema.Contrastenhancementcannotvi44OntheT2WIthereisalesioninthelefttemporallobe,foundincidentally.

TherewasnoenhancementandtheDWIwasnormal.

Duringfollow-uptherewasaslightincreaseinsize.

Thiswasdiagnosedasalow-gradeastrocytoma.

Itisnotpossibletoresectsuchalesion,sincetheinfiltratingtumorscellsarewithinthenormal-appearingbraintissue.OntheT2WIthereisalesion45Ingliomas-likeastrocytomas,oligodendrogliomasandglioblastomamultiforme-enhancementusuallyindicatesahigherdegreeofmalignancy.

Thereforewhenduringthefollowupofalow-gradegliomathetumorstartstoenhance,itisasignofmalignanttransformation.

Gangliogliomasandpilocyticastrocytomasaretheexceptionstothisrule:theyarelow-gradetumors,buttheyenhancevividly.Asdiscussedabove,itrecentlyhasbeenshownthattumorangiogenesisasshownbyperfusionMRcorrelatesbetterwithtumorgradethanenhancementaftertheadministrationofintravenouscontrast.Ingliomas-likeastrocytomas46Low-gradetumorswithenhancementaGanglioglioma(left)andapilocytic

astrocytoma(right)Low-gradetumorswithenhancem47Theamountofenhancementdependsontheamountofcontrastthatisdeliveredtotheinterstitium.

Ingeneral,thelongerwewait,thebettertheinterstitialenhancementwillbe.

Theoptimaltimingisabout30minutesanditisbettertogivecontrastatthestartoftheexaminationandtodotheenhancedT1WIattheend.Theamountofenhancementdepe48Left:SchwannomaextendingintothemiddlecranialfossawithhomogeneousenhancemantRight:PrimarylymphomaknownforitsvividenhancementLeft:Schwannomaextendingint49Noenhancementisseenin:LowgradeastrocytomasCysticnon-tumorallesions:DermoidcystEpidermoidcystArachnoidcyst

Noenhancementisseenin:50Anintra-axialtumorinanadultcenteredinthetemporallobeandinvolvesthecortex.

Massiveinfiltrativegrowthinvolvingalargepartoftherightcerebralhemisphere,withminimalmasseffect&noenhancement.

Thesearetypicalforalow-gradeastrocytoma.Anintra-axialtumorinanadu51Homogeneousenhancementcanbeseenin:MetastasesLymphomaGerminomaandotherpinealglandtumorsPituitarymacroadenomaPilocyticastrocytomaandhemangioblastoma(onlythesolidcomponent)GangliogliomaMeningiomaandSchwannomaHomogeneousenhancementcanbe52Brain-Tumor---Systematic教学讲解课件53Patchyenhancementcanbeseenin:MetastasesOligodendrogliomaGlioblastomamultiformeRadiationnecrosis

Patchyenhancementcanbeseen54Aglioblastomamultiforme(GBM).

Theenhancementindicatesthatthisisahigh-gradetumor,butonlypartsofitenhancewithacysticcomponentwithringenhancement.

ThetumorcellsprobablyextendbeyondtheareaofedemaasseenontheFLAIRimage,becausegliomasgrowinfiltrativelyintonormalbrain-initiallywithoutanyMRchanges.Aglioblastomamultiforme(GBM55Alargetumorislocatedintherighthemispherewithlimitedmass-effect,indicateingthatthereismarkedinfiltrativegrowth.HeterogeneityonbothT2WIandFLAIR.Thereispatchyenhancement.

AllthesefindingsaretypicalforaGBM.

Virtuallynoothertumorbehavesinthisway.Alargetumorislocatedinth56Brain-Tumor---Systematic教学讲解课件57ThreedifferentringenhancinglesionsThreedifferentringenhancing58Conspicuityoftumorswithcontrast

ThecaseontheleftdemonstratesthevalueofGadoliniumintheconspicuityoftumors.

ThisisapatientwithNeurofibromatosisII.

Aftertheadministrationofcontrastthetwomeningiomasandtheschwannomaareeasilyseen.Conspicuityoftumorswithcon59Leptomeningealmetastasesareusuallynotseenwithouttheadministrationofintravenouscontrast.

Thecaseonthetopdemonstratestheabnormalenhancementalongthebrainstem,alongthefoliaofthecerebellum(yellowarrow)andalongthefifthintracranialnerve(bluearrow)inapatientwithLeptomeningealmetastases.Leptomeningealmetastasesare60SkullbaseCommonskullbasetumorseitherarisefromextracranialstructureslikethesinuses(sinonasalcarcinoma),orfromtheskullbaseitself(chordoma,chondrosarcoma,fibrousdysplasia).

Chordomaisusuallylocatedinthemidline,whilechondrasarcomausuallyarisesoffthemidline.Differentialdiagnosis

forspecificanatomicareaSkullbaseDifferentialdiagnos61Brain-Tumor---Systematic教学讲解课件62Amidlinetumorarisingfromtheclivus.

Thisisthetypicalpresentationofachordoma.

Thedifferentialdiagnosiswouldincludeametastasisandachondrosarcoma.Amidlinetumorarisingfromt63Anotherskullbasetumorlocatedoffmidline.

Thisisatypicalpresentationforachondrosarcoma.

Thedifferentialdiagnosiswouldincludeametastasisandaparaganglioma.

Chondrosarcomascanbelocatedinthemidlineandchordomasaresometimeslocatedoffmidlinebutthosecasesareexceptional.Anotherskullbasetumorlocat64AnexampleofaSkullBaseParaganglioma.AnexampleofaSkullBasePar65A58-year-oldmalewithagradualonsetofrightfacialpain

andnumbnessandarecentonsetofdoublevision.

Thereisanenhancingmassanteriortotheskullbaseandalsointheregionoftherightcavernoussinus.

Inthebonewindowsettingthereissclerosisoftheskullbase,particularlyintheregionoftheclivus.

ContinuewiththeMRimages.A58-year-oldmalewithagrad66Themoststrikingfindingistheblackclivusduetothesclerosis.AnormalclivusisbrightonT1WIasaresultofthefattybonemarrow.

Thereisanenhancingmassanteriortotheclivus.

Onthecoronalimagesweseetheenhancementextendingthroughtheforamenovaletotherightofthecavernoussinus.

ThediagnosisisaNasopharyngealsquamouscellcarcinomawithintracranialextension.

Themoststrikingfindingist67Sella/suprasellar：InthisregionitisimportanttokeepthepossibilityofanAneurysminthedifferentialdiagnosis.Sella/suprasellar：Inthisreg68Imagesofamassinthesuprasellarcistern.

OntheNECTwecanseethatitcontainscalcium.

OntheT1WIthereisahyperintenseareathatshowsnoenhancement(i.e.cystic).

Thereareothercomponentsthatshowenhancement.

Withahydrocephalus.

ThesefindingsareveryspecificforaCraniopharyngeoma.Imagesofamassinthesupras69OntheleftNECTandenhancedCT-imagesofa33-year-oldfemalewithsevereheadache(worseinthea.m.),reductioninvisualacuityandvisualfieldsandpapilledema.

ContinuewiththeMRimages.OntheleftNECTandenhanced70Noticethenormalinferiorlydisplacedpituitarygland.

Thismeansitisnotamacroadenoma.

ThediagnosisisagainaCraniopharyngioma.

Thedifferentialdiagnosiswouldincludeanastrocytomaandameningioma.

Noticethenormalinferiorlyd71Cerebello-pontineangle

Cerebello-pontineangle72A52-year-oldmalewithhearinglossontheright.

Theimagesshowanunusualcysticmasswithenhancingseptations.

Thereisalsosomeenhancementwithintheinternalacousticcanal.

Basedontheimagesthemostlikelydiagnosiswouldbeacysticschwannoma,butthishappenedtobeanuncommon,cysticpresentationofaMeningioma.A52-year-oldmalewithhearin73Brain-Tumor---Systematic教学讲解课件74Ontheleftatumorlocatedinthepinealregion.

Basedontheseimagesthedifferentialdiagnosiswouldinclude:MeningiomaPineocytomaGermCellTumor

Thishappenedtobeameningioma.Ontheleftatumorlocatedin75Ontheleftaretypicalimagesofarupturedpinealregiondermoid.Ontheleftaretypicalimages76Ontheleftimagesofa40y/ofemalewithblurredvisionandmemorydecayforonemonth，graduallstoit，nauseaandvomiting.ThisisanOligoastrocytoma

Grade3.Ontheleftimagesofa40y/o77Ontheleftimagesofa12y/omalewithupwardgazeparalysis.

Thereisatumorlocatedinthepinealregion.

Thetumorcontainscalcifications.

Thereishomogeneousenhancement,whichiscommonforatumorinthepinealregion(discussedabove).

Basedontheageofthepatient,thelocationandthetumorcharacteristics,thisismostlikelyaGerminoma.Ontheleftimagesofa12y/o78Intraventricular

Intraventricular79Ontheleftatumorlocatedinthe3rdventricle.

Thetumorcontainscalcifications.

ThediagnosisisaGiantcellastrocytoma.Ontheleftatumorlocatedin80Brain-Tumor---Systematic教学讲解课件814thventricleInchildrentumorsinthe4thventricleareverycommon.

Astrocytomasarethemostcommonfollowedbymedulloblastomas(orPNET-MB),ependymomasandbrainstemgliomaswithadorsalexophyticcomponent.Inadultstumorsinthe4thventricleareuncommon.

Metastasesaremostfrequentlyseen,followedbyhemangioblastomas,choroidplexus

papillomasanddermoidandepidermoidcysts.4thventricle82MedulloblastomaMedulloblastoma83

Manynon-tumorouslesionscanmimicabraintumor.

Abscessescanmimicmetastases.

Multiplesclerosiscanpresentwithamass-likelesionwithenhancement,alsoknownastumefactivemultiplesclerosis.

Intheparasellarregiononeshouldalwaysconsiderthepossibilityofaaneurysm.

TumorMimicsTumorMimics84Brain-Tumor---Systematic教学讲解课件85InfectionsandvascularlesionscanalsomimicaCNStumor.Infectionsandvascularlesion86

Thanksforyourattention!Thanksforyourattention!87BrainTumor-SystematicApproach

byRobinSmithuisandWalterMontanera

河南省人民医院放射科

高明译讲BrainTumor-SystematicAppro88IntroductionIncidenceofCNStumorsAgedistributionTumorspreadIntra-versusExtraaxialMidlinecrossingMultifocaldiseaseCorticalbasedtumorsCTandMRCharacteristicsBrain-Tumor---Systematic教学讲解课件89Fat-Calcification-CystHighonT1LowonT2DiffusionweightedimagingPerfusionImagingEnhancementDifferentialdiagnosis

forspecificFat-Calcification-Cyst90Brain-Tumor---Systematic教学讲解课件91Brain-Tumor---Systematic教学讲解课件92Brain-Tumor---Systematic教学讲解课件93Brain-Tumor---Systematic教学讲解课件94Brain-Tumor---Systematic教学讲解课件95Brain-Tumor---Systematic教学讲解课件96Brain-Tumor---Systematic教学讲解课件97Schwannomalocatedinthecerebellopontineangle(CPA)

withtypicalsignsofanextraaxialtumorSchwannomalocatedinthecere98Meningiomawithabroadduralbaseandaduraltail，hyperostosisintheadjacentbone，enhanceshomogeneously，noblood-brain-barrierMeningiomawithabroaddural99Melanomametastasiswithgraymatterontheanteromedialsideofthelesion(redarrow)，intra-axial.

Melanomametastasiswithgray100Ependymomawithextensiontothecerebellopontineangle(bluearrow)andintotheforamenmagnum

(redarrow)ortothecisternamagnaEpendymomawithextensiontot101Toassesstheextentofatumor.

Anextra-axialtumorintheregionoftheleftcavernoussinuswithhomogeneousenhancementandabroadduraltail.

Thisistypicalforameningioma.Toassesstheextentofatumo102Actualextentofthistumorisgreaterthanexpected.

Thetumorissituatedinthepterygopalatinefossaandextendsintotheorbit.

Italsospreadsanteriorlyintothemiddlecranialfossa.Actualextentofthistumoris103Considerationfortheeffectonthesurroundingstructures.Primarybraintumorsarederivedfrombraincellsandoftenhavelessmasseffectfortheirsizethanyouwouldexpect,duetotheirinfiltrativegrowth.Thereisnoenhancementsothiswouldprobablybealow-gradeastrocytomaConsiderationfortheeffecto104Brain-Tumor---Systematic教学讲解课件105Theabilityoftumorstocrossthemidline

Glioblastomamultiforme(GBM)frequentlycrossesthemidlinebyinfiltratingthewhitemattertractsofthecorpuscallosum.

RadiationnecrosiscanlooklikerecurrentGBMandcansometimescrossthemidline.

Meningiomaisanextra-axialtumorandcanspreadalongthemeningestothecontralateralside.

Lymphomaisusuallylocatednearthemidline.

Epidermoidcystscancrossthemidlineviathesubarachnoidspace.

MScanalsopresentasamasslesioninthecorpuscallosum.Theabilityoftumorstocross106Left:MetastasesRight:MultiplemeningiomasandaschwannomainapatientwithNeurofibromatosisIILeft:Metastases107

Multifocaldisease:

Metastaticdisease

lymphomas

MulticentricGlioblastomamultiforme(GBM)

Gliomatosiscerebri

Seedingmetastases:Medulloblastomas,Ependymomas,GBMsandoligodendrogliomas

Phacomatoses:

NeurofibromatosisI:opticgliomasandastrocytomas

NeurofibromatosisII:meningiomas,ependymomas,choroidplexuspapillomas

TuberousSclerosis:subependymaltubers,intraventriculargiantcellastrocytomas,ependymomas

vonHippelLindau:hemangioblastomas

Non-tumorousdiseaseslikesmallvesseldisease,infections(septicemboli,abscesses)ordemyelinatingdiseaseslikeMS

Multifocaldisease:

Metast108Corticalbasedtumors

Mostintra-axialtumorsarelocatedinthewhitematter.

Sometumors,however,spreadtoorarelocatedinthegraymatter.

Thesecorticalbasedtumorsincludesoligodendroglioma,

gangliogliomaandDysembryoplastic

NeuroepithialTumor(DNET).

Thedifferentialdiagnosisincludesnon-tumorouslesionslikecerebritis,herpessimplexencephalitis,infarctionandpost-ictalchanges.Corticalbasedtumors

Mostint109A45-year-oldfemalewithastableseizuredisorderfor15years.

Thisisaganglioglioma.

ThedifferentialdiagnosisincludesDNETandpilocyticastrocytoma.

A45-year-oldfemalewithast110A10-year-oldmalewithsecondaryepilepsy.

ThisisaDysembryoplastic

NeuroepithialTumor(DNET)..

Brain-Tumor---Systematic教学讲解课件11152-year-oldfemalewhocomplainedofheadacheandneckpainforoneyearwith

arecentonsetoftonic-clonicseizures.Thisisaninfiltratingtumorwhichextendsallthewaytothecortex,

withlimitedmasseffectonsurroundingstructuresandcalcifications.Themostlikelydiagnosisisoligodendroglioma.52-year-oldfemalewhocomplai112Fat-Calcification-CystAruptureddermoidcystwiththeclassicalfindings.

Chemicalshiftartefactindicatesthepresenceoffat,seenonlyinthefrequencyencodingdirection.Fatwithinatumorisseeninlipomas,

dermoid

cystsandteratomas.Sometumorslikelymphoma,colloidcystandPNET-MB(medulloblastoma)canhaveahighdensityonCT.Fat-Calcification-Cyst113Acalcifiedmassinthesuprasellarregion,causingobstructivehydrocephalus.ThislocationandthecalcificationaretypicalforaCraniopharyngioma.

Apineocytomaitselfdoesnotcalcify,butinsteadit'explodes'thecalcificationsofthepinealgland.Acalcifiedmassinthesupras114Thecalcificationandtheextensionofthetumortothecortexareverytypicalforanoligodendroglioma.

Anastrocytomashouldbeinthedifferential.Thecalcificationandtheexte115Apatientwithprogressivevisualloss.OnthecoronalandsagittalT1WIthereisalargemasscenteredaroundthesellawithabroadduralbase.

Thereisextensionintothesella.

Thisisacalcifiedmeningioma.

Apatientwithprogressivevis116

ManycysticlesionscansimulateaCNStumor.Theseincludeepidermoid