医学影像诊断学课件

DiagnosticofUltrasonography

FoundationsofUltrasonographyHistoricalperspectiveofsoundIn1947,K.Dussickmadeoneoftheearliestapplicationsofultrasoundtomedicaldiagnosis.In1948,Dr.HowrydevelopedthefirstultrasoundscannerIn1954,echocardiographictechniquesweredevelopedbyDrs.C.H.HertzandI.EdlerinSweden.In1962,thedevelopmentofthecontactstaticscannerinNorthAmerica.In1972,thenewrevolutionarygray-scaleimagingandimprovedresolutionreal-timescannersweredevelopedClinicalchoiceofimagingtechnique

Simple→complicationone→many(convenient)Nodamage→lessdamage→moredamage(safe)Lowexpense→highexpense(cheap)ComparedwithCT&MRI

灰階超聲成像(greyscaleultrasonictomography)。Advantage:NotexpensiveasCT&MRI,sectionalimaging,real-time,noradiationDisadvantage:ContrastandspatialresolutionofimagingisnotasgoodasCT&MRI.QualitiesofaSonographerIntellectualcuriosityPerseverancetoobtainhigh-qualityimagesAbilitytoconceptualize2Dimagesintoa3DformatQuick-thinkingandanalyticcapabilitiesGoodphysicalheathCommunicationskillsDedicationBasicultrasoundprinciples

Ultrasound:f>20,000Hertz(Hz)Awaveisapropagationofenergythatmovesbackandforthorvibratesatasteadyrate.Soundwavesaremechanicaloscillationsthataretransmittedbyparticlesinagas,liquidorsolidmedium.ComparedwithAudiblesound

Common:essentialqualities;akindofmechanicalvibration;longitudinalwave;spreadinelasticitymedium;akindofenergyconvertDifference:highfrequencyofwave,shortwavelength,spreadalongstraightline,gooddirectivityBasicultrasoundprinciples

Wavelength:representsthedistanceoccupiedbyeachcycle,theoperatingfrequencyofthetransducer,andthevelocityofsound.ThetotaldistanceoccupiedbyasoundpulseisthewavelengthmultipliedbythenumberofcyclesinthepulseandcalledthespatialpulselengthMeasurementofSound:thedecibel(dB)unitisoftenusedtomeasurethestrengthormaderegardingtheratiooftwointensitiesoftwoamplitudesBasicultrasoundprinciples

Frequency:Soundischaracterizedaccordingtoitsfrequency.Inultrasound,frequencyreferstothenumberofoscillationspersecondperformedbytheparticlesofthemediuminwhichthewaveispropagating:1oscillation/sec=1cycle/sec=1hertz(1Hz)1000oscillation/sec=1kilocycle/sec=1kilohertz(1kHz)1,000,000oscillation/sec=1magacycle/sec=1megahertz(1MHz)BasicultrasoundprinciplesVelocityofSound

:determinedbythedensityandelasticpropertiesofthemedium.Thevelocityofsounddiffersgreatlybetweenair,bone,andsofttissue.Thevelocityofsoundvariesbyonlyafewpercentfromonesofttissuetoanother,Air-filledstructures,suchasthelungsandstomach,orgas-filledstructures,suchasthebowel,impedethesoundtransmission.BasicultrasoundprinciplesC=f×λ頻率(f):unit(Hz)聲速(c):unit(m/s)Average:1540m/s,resembleto1500m/s波長(λ):unit(mm).Thefrequencyandwavelengthofcommonlyusedultrasound

f(MHz)0.81.252.53.05.07.510.015.0λ(mm)1.881.200.60.50.30.20.150.1超聲的束射性定義:當聲源的直徑甚大於傳播介質內的波長時,超聲的能量高度集中,呈束狀向前傳播從聲源發出的超聲波最近的一段聲束幾乎平行,這段區域為近場區。遠離此區後,聲束向前稍有擴散，為遠場區。擴散角（θ):擴散的聲束與平行聲束間形成的夾角）;擴散角越小，束射性越好，則方向性越強，探測效果越好;探頭的半徑r越大，則半擴散角就越小BasicultrasoundprinciplesPiezoelectricEffect:thesoundbeamsusedindiagnosticultrasoundareproducedfromatransducerbythePiezoelectricEffect.Thetransducerisameansforconvertingonefromofenergyintoanother(e.g.,electricalenergyintomechanicalsoundwaves).Mostdiagnosticapplicationsuseshort,pulsedultrasoundwavesforoptimumresolution正壓電效應

a.晶體未受外力時，兩側不帶電荷

b.晶體受壓力；c.晶體受拉力。逆壓電效應a.晶體兩側加電場時，長度伸展

c.晶體兩側加與a相反的電場時，長度壓壓縮。BasicultrasoundprinciplesPulse-Echo:therearetwobasicmodesoftransduceroperationthatareusedinmedicaldiagnosticapplications,continuousandpulsed.ThecontinuoussignalisusuallyfoundinDopplerequipment.Pulse-Echotransducersfunctionbysendingoutshortburstsofsoundenergyandthenlisteningforreturnechoinformation.BasicultrasoundprinciplesLongitudinalWaves:ultrasoundisaformofnonionizingradiationinwhichLongitudinalpressureWavesofhigh-frequencyaretransmittedthroughamedium.Therewavesareformedbytheoscillationofparticlesormoleculesare“squeezed”closertogether,orcompressed,andpartundergoexpansion,orrarefaction,bywhichthemoleculesarepulledfartherapart.Assoundtravelsamaterial,alternateregionsofcompressionandrarefactionoccur.BasicultrasoundprinciplesAcousticImpedance:theultrasoundwaveisverysimilartoalightbeaminthatitmaybefocused,refracted,reflected,orscatteredatinterfacesbetweendifferentmedia.Atthejunctionoftwomediaofdifferentacousticproperties,anultrasoundbeammaybereflecteddependingonthedifferenceinacousticimpedancebetweenthetwomediaandtheangleatwhichthebeamhitstheinterface(angleofincidence)人體正常組織的聲阻抗組織器官

密度

g/cm3聲速

m/s聲阻抗（×105瑞利）大腦

1.03815401.588小腦1.03014701.514脂肪0.95514761.410軟組織1.01615001.590肌肉1.07415681.648肝髒1.05015701.648腎髒-1560-顱骨1.65833605.570胎體1.02315051.579羊水

1.01314741.463血液

1.05515701.656眼晶體1.13616501.874肺及腸腔氣體0.001293320.000428SoundReflections:reflectionsmostfrequentlyreceivedarethosethatoccurredataperpendicularincidence.Theangleofreflectionisequaltotheangleofincidence.thisoccursatmostspecularinterfaceswheretheboundaryissmoothandwherethedimensionsoftheinterfacearelarderthanthewavelength(i.e.,diaphragm,wallsofvessels)Soundnotreflectedistransmittedthroughtheinterface.Refraction(changeindirectionofsound)canoccuriftheincidentangleisnotzeroandifthevelocitiesofsoundofthetwomaterialsformingtheboundaryarenotequal.Nonspecularreferstointerfacesthataresmallerthanwavelengthornotsmooth,(l.e.,redbloodcells,liverparenchyma,etc)超聲傳播圖示a發射；b繞射；c散射BasicultrasoundprinciplesImageResolution:

Resolutionistheabilitytoseparatethesmallestreflectorsfromoneanother.Axialresolutionistheminimumreflectorseparationalongthesoundpathrequiredtoproduceseparateechoes.Lateralresolutionistheabilitytoproduceseparateechoesperpendiculartothesoundpathandisaffectedbytransducerdiameterandfocusing.BasicultrasoundprinciplesAttenuation:itisthesumofacousticenergylossesresultingfromaborption,scatteringfromaborption,scattering,andreflection.Inhumansofttissue,soundisattenuatedattherateof0.5dBpercentimeterpermillionhertz.Ifairorboneiscoupledwithsofttissue,moreenergywillbeattenuated.Attenuationthroughacalciuminterfacesuchasagallstonewillproduceashadowwithsharpbordersonthereal-timeimage.中文小結

對人體器官進行探測的基礎：在介質中以直線傳播，有良好的指向性

当超声经两种声阻抗不同相邻介质的界面时，其声阻抗差大于0.1％，而介面又明顯大於波長，即大介面時，則發生反射，一部分聲能在介面後方的相鄰介質中產生折射，超聲繼續傳播，遇到另一個介面又產生反射，直至聲能耗竭。反射回來的超聲為回聲。聲阻抗差越大，則反射越強，如果介面比波長小，即小介面時，則發生散射。

衰减：即振幅與強度減小。衰減與介質的衰減係數呈正比，與距離平方呈反比，還與介質的吸收與散射有關。

多普勒效應（Dopplereffect）：活動的介面對聲源作相對運動可改變反射回聲的頻率。這種效應使超聲能檢查心臟活動和胎兒活動以及血流狀態。

InstrumentationInstrumentation

DisplayModesA-Mode(amplitudemode):producesaone-dimentionalimagedisplayingtheamplitudestrengthofthereturningechosignalsalongtheverticalaxisandthetime(distance)alongthehorizontalaxis.Theamplitudedisplayrepresentsthetimeordistanceittakesthebeamtostrikeaninterfaceandreturnthedigaltothetransducer.Thegreatertherefectionattheinterface,thetallertheamolitudespikewillappear.大腦A型超聲儀波形圖

Instrumentation

DisplayModesB-Mode

(brightnessmode):methoddisplaystheintensityofanechobyvaryingthebrightnessofadottocorrespondtoechostrength.Grayscalereferstotheconditionofassigningeachlevelofamplitudeaparticularshadeofgray.TheB-Modeisthebasisforallreal-timeimaginginultrasound.肝臟切面的B型超聲成像圖（二維）

DisplayModes

M-Mode(MotionMode):displaystimealongthehorizontalaxisanddepthalongtheverticalaxistodepictmovement,especiallyincardiacstrutures.心臟左室長軸M型超聲心動圖DisplayModes

Real-time:Real-timeimagingprovidesadynamicpresentationofmultipleimageframespersecondoverselectedareasofthebody.Theframerateisdependentinthefrequencyanddepthofthetransduceranddepthselection.DisplayModes

Three-DimensionalReconstruction:Imagesareacquiredontheirx,yandzaxes,manuallyrealigned,andthenreconstructedintoathree-Dimensionalformat.Thistechniquehasbeenusefulinreconstructingthefetalface,ankle,andextremitiesinthesecond-andthird-trimesterfetus.Clinicalinvestigationsarecurrentlyunderwaytodiscoveradditionalapplicationsofthree-Dimensionalimaging.四維：即即時的三維成像技術，可動態的觀察三維圖象；DisplayModes

Doppler:TheDopplerPrinciplereferstoachangeinfrequencywhenthemotionoflaminarorturbulentflowisdetectedwithinavascularstructure.InthemedicalapplicationoftheDopplerPrinciplethesoundwaveisbouncedoffamovingredbloodcell.Ifthecellmovesawayalongthelineoftheultrasoundbeam,theDopplershiftisdirectlyproportionaltothevelocityoftheredcell.Ifthecellmovesawayfromthetransducerintheplaneofthebeam,thefallinfrequencyisdirectlyproportionaltothevelocityanddirectionoftheredbloodcellmovement.DisplayModesColorFlowDoppler:Velocitiesarequantitatedbyallocatingapixeltoflowtowardthetransducerandflowawayfromawayfromthetransducer.Eachvelocityfrequencychangeisallocatedacolor.Colormapsmaybeadjustedtoobtaindifferentcolorassignmentsforthevelocitylevels;usuallyredisassignedtoflowtowardthetransducerandbluetoflowawayfromthetransducer.DisplayModesPulse-EchoInstrumentationComponentpartsincludethepulserandthereceiver.Timegaincompensation(TCG)equalizesdifferencesinreceivedechoamplitudescausedbyreflectordepth.Dynamicrangeistheratioofthelargestsignaltothesmallestsignalthatasystemcanhandle.正常腎動脈血流頻譜圖腎動脈狹窄的血流頻譜圖超聲設備：主要由超聲換能器即探頭（prode）和發射與接收、顯示與記錄以及電源等部分組成DisplayModesTransducerSelectionCurvedarray:lineararraytransducerwithacurvedscanheadandelectronicfocusingLineararray:multiplesmalltransducerelementselectronicallycoordinatedtoproducearectangularimageSector:smalltransducerheadthatproducesapie-shapedimageTransrectaltransducer:specialtransducerthatisintroducedintotherectumtoevaluatetheprostate,bladder,andrectumTransvaginal(endovaginal)transducer:ahigh-frequencyprobethatisinsertedintothevaginatoimgaetheuterus,ovaries,andadnexalarea.

a)線性掃描；b)扇形掃描；c)旋轉掃描Artifacts

Instrumentproblem:occurwhentheequipmentisnotfunctioningproperlyTechnique-dependentartifacts:

theappearanceisproducedbyunsatisfactoryoperatortechniqueUnavoidableartifactsresultingfromthewaytissuesaffectsound.KEYTERMS

Acousticimpedance(聲阻抗):measureofamaterial’sresistancetothepropagationofsound;expressedastheproductofacousticvelocityofthemediumandthedensityofthemedium.Amplitude(波幅):strengthoftheultrasoundwavemeasuredindecibels.KEYTERMS

Angleofincidence(入射角):anglefromthenormalatwhichthesoundbeamsstrikestheinterfaceAngleofreflection(反射角):theamplitudeofthereflectedwavedependsonthedifferencebetweentheacousticimpedancesofthetwomaterialsformingtheinterfaceKEYTERMS

Attenuation(衰減):reductionintheamplitudeandintensityofasoundwaveasitpropagatesthroughamedium;attenuationofultrasoundwavesintissueiscausedbyabsotptionandbyscatteringandreflectionKEYTERMS

Dynamicrange(動態幅度):ratioofthelargesttosmallestsignalsthataninstrumentorcomponentofaninstrumentcanrespondtowithoutdistortion.Framerate(幀速度):rateatwhichimagesareupdatedonthedisplay;dependentonfrequencyofthetransduceranddepthselection.KEYTERMS

Frequency(頻率):numberofcyclespersecondthataperiodiceventorfunctionundergoes;thefrequencyofasoundwaveisdeterminedbythenumberofoscillationspersecondofthevibratingsourceVelocity(速率):inultrasoundthetissuedensitydeterminesthespeedoftheultrasoundwaveWavelength(波長):distanceoverwhichawaverepeatsitselfduringoneperiodofoscillationKEYTERMS

Grayscale(灰階):B-modescanningtechniquethatpermitstheB-modedotstobedisplayedinvariousshadesofgraytorepresentdifferentechoamplitudesKEYTERMS

Realtime(即時):ultrasoundinstrumentationthatallowstheimagetobedisplayedmanytimespersecondtoachievea“realtime”imageofanatomicstructuresandtheirmotionpatternsKEYTERMS

Refraction(折射):changeinthedirectionofpropagationofasoundwavetransmittedacrossaninterfacewherethespeedofsoundvariesResolution(分辨力):abilityofthetransducertodistinguishbetweentwostructuresadjacenttooneanotherKEYTERMS

Piezoelectriceffect(壓電效應):generationofelectricsignalsasaresultofanincidentsoundbeamonamaterialthathasPiezoelectricproperties;intheconverse(orreverse)Piezoelectriceffect,thematerialexpandsorcontractswhenanelectricsignalisapplied.KEYTERMS

Transducer(感測器):anydevicethatconvertssignalsfromoneformtoanother.Spatialpulselength(空間脈衝長度):spatialextentofanultrasoundpulseburstPulseduration(脈衝期):measureoftheringdowntimeofatransducerafterexcitationKEYTERMS

Colorflow:velocityineachdirectionisquantitatedbyallocatingapixeltoeacharea.Eachvelocityfrequencyisallocatingacolor;flowtowardthetransducermaybered;flowawayfromthetransducermaybeblue.KEYTERMS

Frequencyshift(頻移):amountofchangeinthereturningfrequency,comparedwiththetransmittingfrequencywhenthesoundwavehitsamovingtarget,suchasbloodinanartery.Dopplershift(多普勒頻移)：changeinfrequencyofareflectedwave;causedbymotionbetweenthereflectorandthetransducer’sbeam.KEYTERMS

Continuouswave(CW)Doppler:onetransducercontinuouslytransmitssound,andonecontinuouslyreceivessound;usedinhigher-velocityflowpatternsPulsedwave(PW)Doppler:soundistransmittedandreceivedintermittentlywithonetransducer.KEYTERMS

Timegaincompensation(TGC)(時間增益補償)：alsoreferredtoasdepthgaincompensation;abilitytocompensateforattenuationofthetransmittedbeamasthesoundwavetravelsthroughtissuesinthebody;usually,individualpodcontrolsallowtheoperatortomanuallychangetheamountofcompensationnecessaryforeachpatienttoproduceaqualityimage.DescriptiveTerminology

Anechoicorsonolucent(無回聲)Well-definedechogenicwallswithoutinternalechoes;thisstructureidfluid-filledandtransmitssoundeasily.Example:vascularstructure,distentedurinarybladder,gallblander,amnioticcavity.正常血管呈無回聲管狀結構，動脈管壁厚，回聲強，搏動明顯

均質性無回聲：生理：淋巴結病理：淋巴瘤等

DescriptiveTerminologyEcchogenicorhyperechioc(oppositeofanechoic):echo-producingstructure;reflectssoundwithabrighterintensity.Example:gallstone、renalcalyx、bone、fat、fissures、ligaments.皮膚均呈線狀回聲表現。需觀察皮膚有無增厚、變薄或凸出、凹陷時應通過水耦合方式進行

正常皮下脂肪及體內層狀分佈的脂肪呈低水準回聲。當有筋膜包裹時，在脂肪與筋膜之間有時顯出強回聲界限

體內纖維組織與其他組織交錯分佈，一般回聲較強。某些排列均勻的纖維組織其回聲相對較弱。

成骨近探頭側的骨皮質回聲反射很強，後方拖有聲影，骨內結構顯示不清。

DescriptiveTerminologyHeterogeneous(不均勻)：notuniformintextureorcomposition.Example:manytumorshavecharacteristicsofboth“cystic”andsolidtypesofpatterns.DescriptiveTerminologyHomogeneous(oppositeofheterogeneous):Completelyuniformintextureorcomposition.Example:thetextureoftheliver,thyroid,scrotum,andmyometriumarehomogeneous.DescriptiveTerminologyHypoechoic(低回聲):low-levelechoeswithinastructure

Example:lymphnodesandthegastrointestinaltract.軟骨的表現為兩帶狀回聲之間呈為低回聲區。

靜脈管壁薄，回聲弱，搏動不明顯。

DescriptiveTerminologyIsoechoic(等回聲):veryclosetothenormalparenchymaechogenicitypattern.Example:metastaticdiseaseDescriptiveTerminologyIrregularborder:bordersarenotwell-defined,areilldefined,orarenotpresent.Example:abscess,thrombus,metastases.;DescriptiveTerminologyLoculatedmass:well-definedborderswithinternalechoes;theseptamaybethin(likelybenign)orthick(likelymalignant)DescriptiveTerminologyShadowing(聲影):thesoundbeamisattenuatedbyasolidorcalcifiedobject.Thisreflectionorabsorptionmaybepartialorcomplete.Astonewouldcauseasharpshadowposteriortoitsborder.UltrasoundcriteriaTheborderofthestructuremaybesmoothandwell-defined.orirregular.Thetexture(orparenchyma)ofthestructureiseitherhomogeneousorheterogeneous;ifamassispresent,itmaybehypoechoic,echogenic,orisoechoictotherestoftheparenchyma.UltrasoundcriteriaThethroughtransmissionofthesoundiseitherincreased,unchanged,ordecreased.ananechoicmasswillshowincreasedtransmissionofsound,whereasadermiodtumorwillshowdecreasedtransmission.Thecharacteristicofanorganormassissaidtobeeitheranechoic,hypoechoic,isoechoic,hyperechoice,orechgenic.UltrasoundcriteriaTransmissionisalteredbywhetherastructureisacyst,complex,orsolid.Cyst:Smooth,well-definedborders,anechoic,increasedtransmission.Complex:Hascharacteristicsofbothcystandsolid(abscess)Solid:lrregularborders,intemalechosedtransmission.正常人體組織回聲反射的強弱規律

強反射：乳房內纖維護組織→胎盤→胰腺→肝臟。較強反射：骨肉→脂肪→甲狀腺實質。弱反射：脂肪。甚弱反射：無髓鞘中樞神經系統組

織表面反射衰減程度纖維組織強大軟組織中一般脂肪弱小液性無衰減幾不增加鈣化甚強甚大（後方極為模糊）良性病變中一般惡性病變弱大病變在B型（單掃描）圖上的一般規律

囊性與實質性病變的聲象特徵

囊性病變實質性病變邊緣回聲光滑光滑或不光滑腫塊形態圓球或橢球形不規則或規則邊緣折射效應有無（如具纖維包膜，同樣存在）內部回聲無有後部情況加強陰影周圍組織被壓反應性良性、惡性病變聲象圖比較

良性病變惡性病變邊緣回聲光滑不光滑（不一定）腫塊形態較規則常較不規則（不一定）內部回聲中度、均勻或不均勻低弱、部份可增強、不均勻，分佈常不規則後部情況衰減程度一般通常衰減甚大（不一定）周圍組織反應性浸滑潤性（不一定）USG檢查技術多用仰臥位，也可其他體位。切面方位可用橫切、縱切或斜切面。患者採取適宜體位，露出皮膚，塗耦合劑，以排除探頭與皮膚間的空氣，探頭緊貼皮膚掃描，掃描中觀察圖像，必要時凍結，即停幀，行細緻觀察，做好記錄，並攝片或錄影。應注意器官的大小、形狀、周邊回聲，尤其是後壁回聲、內部回聲、活動狀態、器官與臨近器官的關係及活動度等。超聲即時顯像圖像方位標準腹面橫切面圖：圖左為人體的右，圖右為人體的左，圖上為腹，圖下為背。腹面縱切面圖：圖左為頭端，圖右為足端，圖上為腹，圖下為背。背面橫切面圖：圖左為人體左側，圖右為人體右，側圖上為背，圖下為腹。背面縱面圖：圖左為頭端，圖右為足端，圖上為背，圖下為腹。腹面斜切成圖：圖左為人體的右側，圖右為人體的左側，圖上為腹，圖下為背。

常用切面：橫切面常用切面：縱切面

常用切面：斜切面

常用切面：冠切面橫切面

縱切面

投影片2之44OverviewofRSTissuecomponentofchestDensitydifferenceintheareaNaturalcomparisonImagingmodalitieswhichcanbechosenforRSTissuecomponentofchestSofttissueSkin,muscle,mediastinum,breast,diaphragmBonerib,thoracicspine,scapula,clavicle,sternumTracheaandbronchuslungNaturalcomparisonVerygoodnaturalcomparisonHighdensityMediumdensityLowdensityX-rayexaminationsaredependentuponthedensityresolutionImagingmodalitiesforRSX-rayConventionalM:fluoroscopy&radiographySpecialM:tomography&highvoltageradiographyBronchographyCTUltrasoundMRIAdvantagesofConventionalMFluoroscopyfast,convenient,cheap,rotatethepatient,functionalchangeofthelung,massscreenRadiographyfast,convenient,staticimagewithsharp&clearmargin,storageofthecase’sinformationforteaching,review,research,andlegalpurposes,etcDisadvantagesofConventionalMFluoroscopyobscureimage,norecordRadiographycan’trotatethepatient,nofunctionalchangescanbeseenMechanismoftomographyTubemotionFilmmotionBronchographyMethodInsertatubeAnesthesiathecarinibifurcationSelectthetargetedbronchustoinjectthecontrastmediaTakingphotographofthebronchus

IndicationofBronchographyBronchiectasisAnyreasonofhemptylysisBronchogeniccarcinomaoflungAbscesses……HazardsmayhappenAllergytoIodineandpurucaine\lidocaine,etcDisseminationofinfection(tuberculosis)throughthebronchusCT:AdvantagesVerysensitivemethodCanusethepost-processingsoftwareanddocoronal,sagittalreformationsHRCTenablesthedetaileddelineationoffinestructuresofthelungCE-CTenablesthedifferentiationofvesselsfromnon-vascularstructures,especiallyusefulforthefindingoflymphadenopathy,TNMstaging,etcCT:disadvantagesIonizationsTransversescaninthepast,howeverwiththedevelopmentofrecenttechnologyofpostprocessingprogramstheproblemisbeingresolvedMRI:AdvantagesWithoutradiationandionizationCandoanysectionscanlikecoronal,sagittal,oraxial,obliqueWiththeflowingvoideffect,thelargevesselsareeasytobedifferentiatedfromothersolidstructureslikeLNs,masses,etcMRI:DisadvantagesNotsensitiveinthedetectionofair,calcification,andvesselsSpatialresolutionisnotashighastheCTimagesDetailedinformationisnotasgoodasCT,HRCTCost:expensiveWilhelmConradRöentgenProfessorofExperimentalPhysicsWürzburgUniversityDiscoveredx-rays8November,1895AwardedfirstNobelPrizeforPhysics1901ProductionofX-raysHighspeede-strikemetalx-rayse-=electronX-raypropertyPenetrationPhotographiceffectPhosphorescentefectIonizationeffectMakingaRadiographAnimalbetweenx-raytubeandx-rayfilmLowenergyphotonsabsorbedbypatientNotusefulforimageproductionFiltersreducepatientexposureOnlypossiblebecauseofdifferentialabsorptionofx-raysPhotoelectriceffectFilmBlacknessEmulsioncrystalsexposedX-raysorlightPrecipitateonfilmduringdevelopmentBlackspotEmulsioncrystalsnotexposedRemovedduringfixingprocessWhitespotFilmBlacknessDegreeofblacknessaffectedbynumberofphotonsstrikingfilmmAnumbertofilmkVpenergynumbertofilmFactorsAffectingImageDetailMotionFilmSpeedFocalspotsizeFocalspot-filmdistanceObject-filmdistanceGriduseDistorsionMotionBigprobleminveterinaryimagingTubehead,patient&/orcassetteSedateoranesthetizeanimalUseshortexposuretimeFocalSpotWheret