醫(yī)學(xué)影像原理介紹

醫(yī)學(xué)影像原理介紹History1895:WilliamK.RoentgendiscoveredX-rays.1901~1930:intensifyingscreen,tomography,andtherotatinganodetube.~1970:nuclearmedicine.ultrasound,CT,~1980:PET,MRI,Microwave.~future:multi-modalityimagesystem,PACS放射醫(yī)學(xué)影像介紹何謂醫(yī)學(xué)影像醫(yī)學(xué)影像種類(lèi)傳統(tǒng)X光影像特殊攝影影像電腦斷層影像核磁共振斷層影像核子醫(yī)學(xué)造影影像其他影像醫(yī)學(xué)影像資訊結(jié)構(gòu)性影像資訊CT,MRI,X-ray,Ultrasound功能性影像資訊

Functional-MRI,NuclearMedicine融合影像資訊CT-SPECT,MRI-SPECTCT-PET,MRI-PETCT-MRICameraprincipleMEDICALIMAGEEQUIPMENTEMWAVESPECTRUMImageSignalTransmissionEmissionMagneticfieldUltrasoundOther:Microwave,laser….RadiationIonization:非粒子輻射X,r–rayNon-ionization:又稱(chēng)為粒子輻射Particle:X-raybasicprincipleX-rayintroductionWhatisX-ray?InteractionsbetweenX-rayandMatter(1)CoherentScattering(2)PhotoelectricEffect(3)ComptonScattering(4)Pairproduction(5)PhotodisintegrationCoherentscatteringPhotoelectriceffectComptonScatterParproductionX-RAYDTETCTORSToproduceanimagefromtheattenuatedX-raybeam,theX-raysneedtobecapturedandconvertedtoimageinformation.TwosystemfortheX-RAYdetectors:Screen-FilmdetectorDetectorsforcomputerradiographySchematicrepresentationoftheradiographicimagechainX-raytubeX-rayTubeX-raygeneratorX-raydetectorsX-rayFilmTheX-rayFilmisaphotographicfilmconsistingofatransparentplasticsubstratemadeofacetateorpolyesterusuallycoatedonbothsideswithalight-sensitiveemulsion.OpticalDensityD=Log10(Ii/It)D:theopticaldensityIi:incidentlightintensityIt:transmittedlightintensityX-rayFilmDouble–EmulsionFilmThefilmusedindailyradiologicalpracticeiscoatedonbothsidesofthefilmsubstrate.Itpreventsbendingofthefilm,becausethefilmwillbendifcoatedonlyonesidewhentheemulsionbecomesdryandshrink.Itdoublesfilmcontrast.診斷型X光機(jī)血管攝影X光機(jī)移動(dòng)型X光機(jī)與C型X光機(jī)數(shù)位型X光機(jī)數(shù)位化X光機(jī)(DigitalRadiographicSystem

ClinicalApplicationClinicalApplication傳統(tǒng)式X光的缺點(diǎn)2Dprojectionof3DstructureLostdepthinformationOverlappingplaneCannotdiffersofttissueCannotquantitativeX-RaysComputerTomographyBasicScanningprodureinCTBasicScanningprodureinCTCTgenerationFirstgeneration:onex-raytube,onedetectorSecondarygeneration:onex-raytube,manydetectorsThirdgeneration:onex-raytube,archdetectorarrayFourthgeneration:circulardetector,onex-raytubeThebasicinternalgeometryofathird-generationspiralCTscannerSingle–SliceandMulti-SliceCTMulti-SliceCTdetectorarrayDynamicSpatialreconstructionSystemDynamicSpatialreconstructionSystemElectronbeamCTHalfarchtargetArchdetectorarray

ElectronbeamCT電腦斷層攝影機(jī)電腦斷層掃描儀

1970年代中期電腦斷層掃瞄儀(CT)的出現(xiàn)，使得傳統(tǒng)醫(yī)療診斷影像產(chǎn)生革命性的演進(jìn)。CTimage-BrainBrainStudy,variableslicethicknesses.

Thereare3imagesinthisseries.

HiSpeedNX/iImages

CTimage-ChestLightSpeedSeriesCTimage-ChestHiSpeedX/iSeriesThoraxstudy,0.7secscantime,auto-mAmode.

CTimage-SpineLightSpeedSeriesImagesandCaseStudies-SpineNRIintroductionNuclearmagneticresonance(NMR)isachemicalanalyticaltechniquethathasbeenusedforover50years.ImagetechniquecallMRI.MRIintroductionNon-ionizingradiationMinimallyinvasiveCapableofprovidingexcellentsoft-tissuecontrastwithimaginginanyarbitraryplaneTherecentdevelopmentofflowimagingprovidesthepassivityofperformingNMRangiographyMRIintroduction1946F.BlockandE.PurcellSpectroscopictechniqueinchemistryandphysics1952BlockandPurcellawardedNobelPrize1973NMRappliedtoimagingtechnique1973~NRIinclinicalfieldMRIbasicprincipleEMwaveC=3*108m/secByMaxwell’swavetheoryE:electricfieldB:magneticfieldEandBhassamefrequency

EMwaveapplicationlistMRIprincipleMRIprincipleSpinMRIprincipleMRIbasicprincipleAnyspinningchargeparticlecreatesanEMfieldSpinquantummember“s”s(1H)=1/2Thenumberofenergystatesofanucleususdeterminedbytheformula#ofenergystat=2s+1MRIbasicprincipleLarmorequation

MRIBasicprincipleMRIBasicprincipleMRIimagehardwareMRIcoilMRIimagehardwareMRIImageDrawingoftheabdominal/pelviscoil.Sagittalpelvisimageobtainedusingtheabdominal/pelviscoil.

Bilateralhipimageobtainedusing

theabdominal/pelviscoil.

0.5T磁振造影機(jī)0.5TSIGNAContour磁共振儀

1.5T磁振攝影機(jī)1.5TSIGNAMR/i磁共振儀

3T磁振造影機(jī)3.0TSIGNAMR

高磁場(chǎng)磁共振儀

高磁場(chǎng)全身性?huà)呙榇殴舱駜x,其特殊的性能可滿(mǎn)足您臨床領(lǐng)域與專(zhuān)業(yè)研究的需求.尤其於神經(jīng)方面的應(yīng)用:RealTime功能性影像,DWI,頻譜分析.MRIimageprincipleMRIimageprincipleMRIimageprincipleMRIimagereconstructionMRIimagereconstructionMRIimage-AngiographyAxialhead,22cmFOV,45.6mmThk,GE(20o),TR/TE=33.33/3ms,1Nex,256x224matrixMRIimage-NeckCoronalheadwithpathology,22cmFOV,2.5mmThk,GE(30o),TR/TE=11/2ms,1Nex,256x192matrixMRIimage-spineSagittallumbarspine,32cmFOV,3mmThk,256x256matrix,2Nex,SE

A)TR/TE=600/15

B)TR/TE=4000/96

C)TR/TE=2000/16ABCWhatisNuclearmedicine?

NuclearmedicineFunctionalimagestudyEmissiondetectionRadionuclideandPharmaceuticalShorthalflife,lowradiation

核醫(yī)診斷常用之同位素伽傌閃爍造影機(jī)GammaCameraPMT(光電倍增管)GammacameradetectorImageapplication ImagemathematicsBackgroundsubtractionNormalizationRegionofinterestinformationCurvegenerationManipulationSimplecalculationswithvalueobtainedfromtheseprocedingoperationNuclearmedicineimage-boneTL201Myocardialperfusionstudy3DImagereconstructionAutoSPECT-BrainAutoSPECT-HeartMyocardialfunctionstudyPositronEmissionTomographyNuclearmedicine:radiotracer/isotopeGammaray->gammacamera->radionuclideimagesActivity/countEmissioncomputedtomography(ECT)SPECTPETSinglephotonradionuclide:Tc99m,Tl201,I131,Ga67Positronemitter:C-11,F-18,N-13,O-15PET:measuringbiochemicalandphysiologicfunctionMRI:hydrogen,limitedinformationintheevaluationofmetaboliceventsPETintroductionRequirementofPETstudies:Positron-emittinglabeledcompoundsPositroncameraTracerkineticmodelsPET(positronemissiontomography)Electrone-Positrone+1800.25511kev-ray511kev-rayAnnihilatione++e-->2-ray(511kev)PET的基本原理PET常用之核種與藥物18FDGPETimageBronchialCarcinomaBreastCaFMISOPETimagingstudyLagercerebellarAVMontheleft.A.T1weightedMRI.TheAVMischaracterizedbythesignalvoidbutflow-inducedvariationsinsignals.B.FDG-PETscanshowsglucosehypomet