医学影像-正常颅脑CT和MRI影像表

CTANDMRIIMAGINGOFNORMALBRAINNORMALANATOMYOFBRAINBrainisseparatedfromcalvariumbythreemeninges-duramater,arachnoidmembraneandpiamater.Dividedintosupratentorialandinfratentorialcompartmentscontaining:-Supratentorium:CerebralhemispheresdiencephalonInfratentorium:BrainstemstructurescerebellumEachcerebralhemisphereisfurtherdividedintoFrontal,Parietal,TemporalandOccipitallobesbyfissuresBRAINANATOMYSagittalsurfaceLatventGenuFornixPituitaryglandMidbrainPonsMedullaCingulategyrusQuadrigeminalcisternSpleniumColliculi4thventCerebellumThalamusSagittalsurfacei.Pinealglandii.Sup.colliculiiii.Inf.Colliculiiv.Aqueductofsylviusv.Midbrainvi.Cerebellumvii.4thventricleviii.Ponsix.Oculomotornx.Interthalamiccommissure109InferiorsurfaceInterhemisphericfissureTemporallobeMammillarybodiesFrontallobeOlfactorytractOptictractPit.stalkponsMedullaoblongataCerebellumVermisBrainstemstructuresMidbrain:dividedintoCerebralpedunclesandcolliculi.Supcolliculiattachedtomed.Geniculate&InftolateralGeniculatebodySurroundedbyPeri-mesencephaliccistern.Pons:dividedintotectumandtegmentumConnectsmidbraintomedullaMedulla:continuesasspinalcordContainsascendinganddescendingSpinaltractsCerebellumDividedintotwohemispheresbyfalxcerebelliConnectedinthemidlinebyawormlikestructure-VermisDividedintoI.Anteriorlobeii.MiddlelobeIii.Flocculo-nodularlobeVentriclesofbrainLateralventricle:-Cshapedcavitywithbodyintheparietallobeandextensionsinthefrontaltemporal,occipitallobesConnectedtothirdventriclebyforamenofmonro.Thirdventricle:-liesb/wtwothalami.connectedtofourthventriclebycerebralaqueduct.Fourthventricle:-liesinthecerebellumCSFFlow:-Lat.vent-foramenofmonro-3rdvent-cerebralaqueduct-4thvent-foramenofmagindieandluschka-subarachnoidspacefinallyabsorbedbythearachnoidgranulationsVentriclesofbrainBloodsupplyofthebrainBloodsupplyofthebrainByInternalCarotidandVertebralAInternalcarotidA:MiddlecerebralAAntcerebralAPost.communicatingAAnt.ChoroidalAVertebralAs:-twoVertebralasjointoformBasilarABranches:AntinfcerebellarASupcerebellarAPontineAs&labyrinthineAsPostcerebralAContd….DividesintocorticalandperforatingAPerforatingAssupplyBasalganglia,Thalami,internalcapsuleThalamus:-PerforatingbrofPCAInternalcap:-Med&latstriatebrofMCA,recurrentbrofACA,AntchoroidalAMidbrain:-Post.cerebralandSupcerebellarAPons:-PontinebrofBasilarACerebellum:-Sup.cerebellarA,Ant.infcerebellarA,PostinfcerebellarAMedulla:-Ant&PostspinalA,PICABloodsupplyofthebrainRed:-MCABlue:-ACAGreen:PCACircleofwillisVenoussinusesofbrainStraightsinusTorculaherophiliOccipitalsinusTransversesinusSup.SagittalsinusInf.SagittalsinusVenoussinuses..TransversesinusStraightsinussigmoidsinusPitutiaryglandICA3rdCN4thCN6thCNSphenoidboneViViibrOf5thCNAxialsectionCingulategyrusCaudateheadPinealglandCorpuscallosumLentiformnucleustrigoneSup.cerebellarcisternInt.capsuleThalamusCoronalsectionCTTechniquePatientiskeptinsupinepositionandheadisplacedinthegantryunderthecursors.Axialsectionsaretakenatanangleof10-13degreetothecanthomeatalline.Slicethickness:-Posteriorfossa:-5mmSupratentorialstructures:-10mmPituitaryglandandsellarregion:-1-3mm(coronalsections)CONTRASTSTUDIES:donebyinjecting100mlof60%iodinatedcontrastcontd..Normalenhancement:Arterial&venousstructuresDuralstructures:-falx,tentoriumChoroidplexusPituitaryglandIndicationsofCECT:I.Infections:ringenhancinglesionsegtuberculoma,neurocysticercosis,Meningitis,Encephalitisii.Tumours:astrocytomas,meningiomasiii.Vascularlesions:aneurysms,AVmalformationsContraindicationsofCECT:I.historyofallergy,renalfailureii.acutehaemorrage;Axialsections-TopogramForCTAxialsectionsaretakenatanangleof10-13degreetotheCanthomeatallineForMRIsectionsareparalleltothereferencelineCTBraincontd…NormalHUvaluesinNCCTbrainGraymatter:-+36-42HUWhitematter:-+26-34HUCSF:-+4-11HUBone:-+200to+1000HUCalcification:-+100to+220HUBlood:-+56-80MRIImagingMultiplanarmodlitysosectionscanbetakeninaxial,coronalandsagittalplanesSlicethicknessissameasCTimaging.RoutinelyappliedsequencesareT1WeighetedspinechoT2WeighetedspinechoProtondensityimagesAnatomyofbrainisbetterexplainedonT1WseqwhilepathologiesarebetterstudiedonT2WandProtondensitysequences.TISSUECHARACTERISTICSSeqParametersCSFGrayMWhiteMFatT1WshortTRHypoisohyperhypershortTET2WshortTRhyperisohypoiso/longTEhypoProtonlongTRisoIsoiso/hypohyperdensityshortTEbloodvesselsappearsignalvoidinallthesequencescalcificationandfibroustissueappearhypointenseinallsequencesMRIAxialsectionaboveforamenmagnumMaxillarysinusBasilarA.MedullaCerebellarhemisphereCisternamagnaTonsilsPetrousboneSphenoidsinusNasalcavityZygomaticarchCTAxialsectionaboveforamenmagnumFrontalsinusSphenoidsinusTemporallobeBasilarA.MastoidcellsCerebellarhemisphereCisternamagnaMedullaOpticnervePituitarySphenoidboneTemporalboneCerebellartonsilsMRIAxialSectionat4thVentricleLensOpticnervePituitaryTemporallobeMiddlecerebellarpeduncle4thVentricleMedialrectusLateralrectusPonsPetroustemporalboneCerebellarhemisphereCTAxialsectionat4thventricleFrontalsinusFrontalboneMid.cerebralABasilarA.Pons4thventcerebellumMidcerebellarpedunclePetrousboneTemporalh