超声基础知识（英文版）.pptx

超声基础知识（英文版）.pptx

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Contents超声基础知识,ppt课件,1,UltrasoundHistoryandprincipleBasicImagePerformanceKnowledgeUltrasoundartifacts,UltrasoundHistory,ppt课件,2,Sonar,SoundNavigationandRanging,ppt课件,3,Sonar,AnicehilldistroyedTitanic,ppt课件,4,GermanU-SubmarineduringWWII,A-Mode,Amplitudemode,ppt课件,5,M-Mode,Motion-ModeM:

MotiondisplayedovertimeTime,ppt课件,6,Depth,Function:

todisplaytissuemotion,1950s,B-Mode,Brightness-modeB:

Brightnessdisplayedasdotsonscreenstrongersignal,brighterdot,ppt课件,7,Function:

todisplaytissuestructureBmodeisalsocalled2Dmode.,B-Mode,ppt课件,8,B-Mode,HP70020A,1981,TOSHIBASDS-10A,1981,ppt课件,9,Doppler-Mode,ChristianAndreasDopplerAustriaPhysicistandmathematicianBornin1803inSalzburgFoundDopplerPrinciplein1842Diedin1853inVenice,ppt课件,10,Doppler-Mode,Soundsource:

NOTmoving,Soundsource:

moving,ppt课件,11,Doppler-Mode,ppt课件,12,Doppler-Mode,BloodcellNOTmoving,Bloodcellmoving,forward/backward,ppt课件,13,Doppler-Mode,v,f+fD,ppt课件,14,fD:

Dopplershiftofthefrequencyf:

Transmittedfrequencyv:

Velocityoftheblood:

Angleofincidencebetweentheultrasoundbeamandthedirectionoftheflowc:

speedofsoundintissue,PWMode（Pulse-Wave）,PW:

Pulse-WaveDoppler,Function:

tomeasurevelocityofbloodflow,VelocityTime,1959,ppt课件,15,PWMode,SampleVolumeAngleCorrection,SampleLine,Grayscalestandsfor:

theamountofallobjectsinthatvelocityinthesamplevolume.,ppt课件,16,PrincipleofPW,Elementsarebothtransmittingandreceivingsoundwaves.ThetransmittingandreceivingofsoundwavesareNOTinthesametime.ThereisaSampleVolume.,PRF:

PulseRepetitionFrequency,Transmit,Receive,Transmit,Receive,ppt课件,17,CWMode（continuouswave）,Function:

tomeasurevelocityofbloodflow,especiallyinheart,CW:

Continuous-WaveDopplerspeedofbloodcellsdisplayedonatime/velocitygraphTime,ppt课件,18,Velocity,1956,CWMode,SensitiveRegionAngleCorrection,SampleLine,Grayscalestandsfor:

theamountofallobjectsinthatvelocityalongthesampleline.,ppt课件,19,PrincipleofCW,Someelementsaretransmittingsoundwaves.Theothersarereceiving.ThetransmittingandreceivingofsoundwavesareJUSTinthesametime.,ppt课件,20,ThereisNOSampleVolume.Butthereisasensitiveregion.,ColorMode,ColorDoppler:

Pixelsassignedcolorbasedonmeanvelocity,Function:

todisplaydirectionofbloodflow,ColormodeisalsocalledCDFImode（ColorDopplerFlowImaging）orCFM（colorflowmapping）,RedtowardsprobeBlueawayfromprobe,ppt课件,21,1983,PowerMode,PowerDoppler:

Pixelsassignedcolorbasedonmeanpower,ppt课件,22,PowermodeisalsocalledCPAmode.（ColorPowerAngio）Function:

todisplayvolumeofbloodflow,especiallyatlowvelocity,DirPowerMode,ppt课件,23,ColorMaps,GrayScale,ppt课件,24,Velocity,Power,DirectionalPower,Bmode,Colormode,Powermode,Difference-Color&colorize,Bmode-colorizedWholeimageiscolorized.,ppt课件,25,ColormodeOnlybloodflowiscolorized.Tissueismonochrome.,Difference-Color&Power,PowerDopplerdisplaysamplitudeofsignal（howmuch）ColorDopplerdisplaysvelocity（howfast）,ppt课件,26,AngleDependent,Colormode,vertical,ppt课件,27,oblique,Powermode,AngleDependent,Yes,No,Atperpendicularangle,Noflowdisplayed,Displayednormally,Difference-PW&CW,Velocit,LocatApplicatio,ransmitting,undwaves.,yLoweSamplevolumenAll,SamplelineCardiology,Continuouswave,PWmodePrinciplePulsed-waveAllelementsaretandreceivingsoProbeAll,CWmode,SampleVolume,AngleCorrection,SampleLine,SomeelementsaretransmittingsSoeunnsditiwveavReesg.ionTheothersarereceiving.,PhasedarrayA,npgelencCilo,rortehcetrionHigh,SampleLine,ppt课件,28,ImagePerformanceKnowledge,ppt课件,29,HowtodefineagoodB-modeimageHowtodefineagoodColorimageHowtodefineagoodPW/CWimage,B-ModeImage,UltrasoundWaveDemonstrationT,Object,Refraction,Reflection,Scatter,ppt课件,30,B-ModeImage,S/Nratio（Signal/NoiseRatio）信噪比,Muchnoiseincavity,ppt课件,31,B-ModeImage,Penetration穿透力,Penetrationgoesto17.50cm,Onlypenetratesat16.04cm,ppt课件,32,B-ModeImage,Spatialresolution空间分辨率,Horizontal,ppt课件,33,Logitudinal,B-ModeImage,Contrastresolution对比分辨率,ppt课件,34,B-ModeImage,Temporalresolution,时间分辨率,ppt课件,35,ColorImage,Sensitivity敏感性,Bettersensitivity小血管血流非常丰富,ppt课件,36,ColorImage,SpatialResolution空间分辨率,Rightimagehasbetterspatialresolution,noobviouscoloroverlayonvesselwall,ppt课件,37,ColorMode,TemporalResolution时间分辨率也称血流动态感,ppt课件,38,PWImage,Sensitivity,敏感性（低速，深部血流）,ppt课件,39,PWImage,Spectrum,Shape频谱形态（包络连续性以及声窗）,ppt课件,40,CWImage,Sensitivity敏感性（在狭窄和返流下的高速血流）,ppt课件,41,UltrasoundArtifacts,ppt课件,42,Side-lobeartifact（旁瓣伪像）Acousticshadowing（声影）Acousticenhancement（回声增强）Slice-thicknessartifact（容积效应）Mirrorimageartifact（镜面伪像）Reverberations（混响）Edgeshadowing（边界声影）,Side-lobeArtifact,Side-lobeartifact:

Intestinalgas（I）isastrongreflectorthatisprojectedintotheinteriorofthegallbladder（Gb）.S=side-lobeartifact,T=transducer,ppt课件,43,Side-lobeartifact:

Thearrowsindicateaside-lobeartifactinastonefreegallbladder（GB）.Theartifactiscausedbygasintheadjacentduodenum（DUO）,AcousticShadowing,Acousticshadowing:

Astrongacousticreflector（e.g.,agallstone=G）castsanacousticshadow（S）duetoreflectionandabsorption.T=transducer,ppt课件,44,Typicalacousticshadow（S）associatedwithagallstone,AcousticEnhancement,Acousticenhancement:

Becausesoundwavesarelessattenuatedinfluid,theechoesbehindafluid-filledstructurehavegreateramplitude.T=transducer,C=cyst,AE=acousticenhancement,Posterioracousticenhancement.Anareaofincreasedechogenicity（arrows）appearsbehindthegallbladder（GB）,45,ppt课件,Slice-thicknessArtifact,Slice-thicknessartifact:

Theanteriorandposteriorcystwallsappearthickenedandindistinct.B=beam-widthartifact,T=transducer,Beam-widthartifact:

Transversescanthroughthebladder（B）showspartialthickeningandlackofsharpnessofthebladderwall,especiallyonthefarside（arrow）,46,ppt课件,MirrorimageArtifact,Mirrorimageartifact:

Schematicrepresentationofsoundwavesintheliver（L）reflectedfromthediaphragm（D）,givingrisetoa“mirror-image”liver.T=transducer,LS=supraphrenic“mirror-image”liver,Mirrorimageartifact:

Rightsubcostalobliquescandemonstratestheliver（L）,thediaphragm（D,orlungentryecho）,asubphrenichepatichemangioma,andthereflectedhemangiomaimagedatasupraphrenic,47,ppt课件location（arrows）,Reverberations,Schematicrepresentationoftypicalreverberations（R）occurringbetweenstronglyreflectiveinterfaces（I）.T=transducer,ppt课件,48,EdgeShadowing,Edgeshadowing:

Whensoundwavesencountercystwallsatatangentialangle,theyarescatteredorrefracted.T=transducer,C=cyst,CE=cysticedgeshadows,ppt课件,49,Review,ppt课件,50,UltrasoundHistory:

Dimension:

Line-Plane-VolumeColor:

B/W-ColorImageperformance:

B-mode:

Noise,Penetration,Spatial/Contrast/TemporalresolutionColor:

Sensitivity,Spatial/temporalresolutionPW:

Sensitivity,SpectrumshapeCW:

SensitivityArtifacts:

Stone,cyst,needle,gas,