fundamentals of ultrasound practice - studentvip · • 2000s - introduction of 3d/4d ultrasound,...
TRANSCRIPT
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1. THEMEDICALIMAGINGDEPARTMENT 3
2. THEHISTORYOFULTRASOUND 4
3. ULTRASOUNDEDUCATION 4
4. THEAUSTRALIANHEALTHCARESYSTEM 6
5. MEDICALTERMINOLOGY 8
6. ULTRASOUNDSCANPLANES 10
7. PATIENTPOSITIONING 12
8. VITALSIGNSANDPATIENTMONITORING 12
9. INFECTIONCONTROL 14
10. COMMUNICATION 15
11. SAFEMOVINGANDHANDLING 16
12. ERGONOMICS 18
13. ULTRASOUNDPHYSICS–SOUNDWAVES 18
14. ULTRASOUNDPARAMETERS 20
15. ULTRASOUNDIMAGEGENERATION 20
16. DISPLAYMODES 21
17. ARTEFACTS 22
18. BIOEFFECTS 23
19. THEULTRASOUNDMACHINE 24
20. THEULTRASOUNDEXAMINATION 24
21. UPPERABDOMENULTRASOUNDEXAMINATION 26
22. RENALULTRASOUNDEXAMINATION 29
23. MUSCULOSKELETALULTRASOUNDEXAMINATION 32
24. THYROIDULTRASOUNDEXAMINATION 34
25. OBSTETRICULTRASOUNDEXAMINATION 35
26. GYNAECOLOGYULTRASOUNDEXAMINATION 39
27. BREASTULTRASOUNDEXAMINATION 43
28. SCROTALULTRASOUNDEXAMINATION 45
29. VASCULARULTRASOUNDEXAMINATION 47
30. MEDICOLEGALISSUESINMEDICALSONOGRAPHY 50
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1. THEMEDICALIMAGINGDEPARTMENT
Medicalimagingistheprocessofimagingthebodyinamedicalsettingtodiagnoseinjuryordisease.Itis
splitupintotwocategories:diagnosticortherapeutic.
Medicalimagingmodalitiescaneitherbeionisingornon-ionising.Ionisingradiationisenergyproducedfromanimagingtechniquethatalsointeractswithtissue.Itisradiationthathasenoughenergytocause
anatomtobecomechargedorionised(losesanelectron).
• ConventionalRadiography
- Thefirstmedicalimagingmodality
- WilhelmRoentgendiscoveredx-rayson8Nov1895
- Imageproducediscalledaradiograph
- Itusesx-raysasanenergysource
- X-raysareattenuatedwhentheyinteractwithtissue:canbescatteredorabsorbed
- Radiolucent:appearsdarker,lessattenuation
- Radiopaque:appearswhiter,moreattenuation
• Fluoroscopy
- Usesx-raysasenergysource
- Contrastmediahelpsimprovevisualisation
- Providesreal-timeimaging
• Mammography
- Radiographyofthebreast
- Useslowerx-rayenergy
• ComputedTomography(CT)
- Firstavailablein1970s
- X-rayspassthroughpatientusingrotatingx-raytube
- Tomographicimageproduced:“slice”ofpatient
- Highradiationdose
• NuclearMedicine
- Usesgammax-rays
- Functionalimaging
- Radioisotopeisgiveneitherorally,injectedorinhaledasaradio-pharmaceutical
- Radioisotopedistributesitselfaccordingtophysiologicalfunction
• MagneticResonanceImaging(MRI)
- Usesprotonsinatomstoproduceimages
- Usespowerfulmagneticfieldsandradio-waves
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- Non-ionising
- Tomographicimageproduced
• Ultrasound
- Useshighfrequencysoundwaves
- Soundgeneratedfromtransducer,reflectedsoundwavereturnstotransducer
- Pulseechoprinciple
2. THEHISTORYOFULTRASOUNDDiagnosticultrasounduseshighfrequencysoundwavestoviewandassessstructuresandorganswithin
thebody.
• 500BC-Pythagorasobservedarelationshipbetweensound,pitchandfrequency.Heinventedan
earlysonometer:adeviceusedfordemonstratingtherelationshipbetweensoundfrequency
producedbyapluckedstringandthetension,lengthandmassofthestring
• 400BC-Archytasstudiedpitchrelatedtomovementofvibratingair
• 350BC-Boethiuscomparedsoundwavestoripplesofwater
• 1500-LeonardoDaVincidiscoveredthatsoundtravelsinwavesandtheangleofincidenceisequal
totheangleofreflection
• 1638-GalileoGalileibeganstudyofmodernacousticsthroughthestudyofvibrations
• 1668-Isaacnewtonstudiedthespeedofsoundthroughair
• 1842-ChristianJohannDopplerproposedthe‘Doppler’effect
• 1880-Paul-JacquesCurieandPierreCuriediscoverpiezoelectricity
• 1914-1918-PaulLangevinandConstantinChilowskydiscoveredawaytousethepropertyof
echoingsoundwavestodetectunderwaterobjects(SONAR=SoundNavigationandRanging)
• 1940s-KarlDussikisapsychiatristandneurologistwhodetectedintracraniallesionsand
discoveredone-dimensionalA-modedisplay
- GeorgeLudwig,JohnWildandWilliamFry
• 1950s-DouglassHowryandJosephHolmesproducea2-Dcompoundscannerandthenthe
bistabledisplay(2-Dimagedisplayedinblackandwhite)
- In1959,theultrasonicinstitutebeganinSydneyAustralia,thankstoGeorgeKossoff,DrWilliam
GarrettandDavidRobinson
- DopplerUltrasoundresearchbeganinlate1950sbyDonaldBaker
• 1965-WalterKrauseandRichardSoldnerdevelopedthefirstreal-timescannerinGermany.Itwas
manufacturedas‘Vidoson’bySiemensandusedrotatingtransducers
• 1969-GreyscalingwasdevelopedattheultrasonicinstitutebyKossoffandhisteam
• 1975-“Octoson”wasdevelopedbytheUltrasonicInstituteinSydney.Itisarapidmulti-transducer
water-bathscannerthatproducedhigh-resolutioncompoundscansatarateof1scanpersecond
• 1980s-Transducerdesignimprovedwithresearch
• 1900s-Harmonicimagingimprovedvisualisationofdifferenttypesoftissue
• 2000s-Introductionof3D/4Dultrasound,contrastenhancedultrasound,molecularimaging,fusion
imagingandelastography
3. ULTRASOUNDEDUCATIONTheoriginsofformalultrasoundtraining:
• In1969,theAustralasianSocietyforUltrasoundinMedicine(ASUM)beganfromUltrasonic
Institute(UI)staffandclinicalcollaborators
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• ASUMintroduced–1976–theDiplomaofDiagnosticUltrasound(DDU)establishedfordoctorsand
in1979–theDiplomaofMedicalUltrasonography(DMU)establishedforpara-medicalpersons
(obstetric/vascular/cardiac/general,stillavailabletoday)
Postgraduateultrasoundeducation:
• 1980–RMITestablishedGraduateDiplomainUltrasonography(nolongerofferedhere)
• 1984–pressurefromwithinQLDtodevelopultrasoundcourse–QUTattemptstoaccreditcourse–
notaccomplisheduntil:
• 1989–QUTestablishesMastersofAppliedScience(MedicalUltrasound)withoptoutGraduate
Diploma
• 1992–AustralianSonographersAssociation(ASA)establishedinMelbourne
• 1994–AustralasianSonographersAccreditationRegistry(ASAR)establishedbyASUM,AIR,ASAand
theuniversitiesinvolvedinsonographereducationatthetime
• 1995–firstprivatepracticalultrasoundtraininginstitute,theAustralianInstituteofUltrasound
(AIU)setuponGoldCoast
• Today–thefollowinguniversitiesofferaccreditedpostgraduatequalificationsinAustralia:
CQUniversity,QueenslandUniversityofTechnology,UniversityofSouthAustralia,Monash
University,CurtinUniversityofTechnology,CharlesSturtUniversity,WesternSydneyUniversity.
Andotherorganisationstoofferaccreditedprograms:ASUM(general,cardiac,vascular,obstetric)
andAIHE(general)
InAustralia,thepracticeofsonographyrequires:
- Successfulcompletionofanaccreditedprogram
- RegistrationwithAustralianSonographerAccreditationRegistry(ASAR)- Recommendedmembershipwithoneofthefollowingprofessionsbodies:Australasian
SonographersAssociation(ASA)ORAustralasianSocietyforUltrasoundinMedicine(ASUM)
- ASARprovidesaccreditationofprogramsandsonographers.Overseasqualificationsassessedby
AIR
NationalRegistrationandRegulation
• Registration–ahealthpractitionersnameisonaregisterthatthegeneralpubliccanaccess
• Regulation–practitionersabidebynationallawsregardingtheirpractice
• InAustralia–AHPRA(AustralianHealthPractitionerRegulationAgency)assistsinregulationof
medicalimagingpractitionersexceptsonographers• TheAHPRAisgovernedbytheHealthPractitionerRegulationNationalLaw.Theprimaryaimisto
protectthehealthandsafetyofthegeneralpublic• MRPBA(MedicalRadiationPracticeBoardofAustralia)arepartofAHPRA–primarilyradiographers
andnuclearmedicinetechnologists
SonographerRegulation
- SonographersarenotpartoftheMRPBAorAHPRA
- Sonographyisaself-regulatingprofessionintermsofentrylevelrequirements,educationand
continuingprofessionaldevelopment
- ASARaccreditssonographersandeducationalinstitutions- TomaintainaccreditationsonographersmustundertakeCPD
- Thereisnomandatoryreportingofsonographers
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4. THEAUSTRALIANHEALTHCARESYSTEM
TheAustralianhealthsystemisworld-classinbothitseffectivenessandefficiency:Australiaconsistentlyranksinthebestperforminggroupofcountriesforhealthylifeexpectancyandhealthexpenditureperperson(WorldHealthOrganisation2003)
• Australia’spopulationasat11thMarch2017wasestimatedtobeover24millionpeople(24386
711)–increasingby1personevery1minand24seconds
• TheAustralianpopulationhasagenerallygoodhealthstatus,withanaveragelifeexpectancyat
birthof8.14years(79.2formenand83.7forwomen),oneofthehighestintheworld
• Therearesomegroupswithpoorhealthstatus,notablyAboriginalandTorresStraitIslander
people;otherwisethepatternofdiseaseislikethatofotherdevelopedcountries
• Australia’srobustprivatehealthsectoriscomplementedbyauniversalpublichealthsystemcalled
Medicare
• Wehavethreetiersofgovernment:
- FederalGovernment–Canberrabased
- StateGovernment–capitalcitybased
- LocalGovernment–centrallybasedintheirowncityorshire
FederalGovernmentResponsibilities
• Medicare–nationalschemeprovidingfreeorsubsidisedaccesstomedicalfacilities
• PharmaceuticalBenefitsScheme(PBS)–subsidisesuniversalaccesstothousandsofprescription
medicines
• Rebatesforprivatehealthinsurancepremiums
• Veteranshealthcare
• Researchfunding
• Collectingtaxestopayfortheseschemes
StateGovernmentResponsibilities
• Publichospitals,theirmanagementandadministration
• Breastscreenandimmunisation,deliverythereof
• Fundingandmanagementofcommunityhealthschemes,publicdentalclinics,ambulanceservices,
patienttransportsubsidyschemeetc.
LocalGovernmentResponsibilities
• Community-basedhealthandhomecareservicese.g.localwomen’shealthclinicsincludingpap
smearclinics,farmer’shealthclinics,vaccinationclinics,homecareforthehomebound
• Environmentalhealthe.g.sanitationservices
Issueswiththe3-tiergovernmentsystem
• Bickeringanddisputesoverfunding,alongwithcost-shiftingoccurregularly,especiallybetween
federalandstategovernmentsofdifferentpoliticalpersuasionse.g.LiberalFederalgovernmentvs
StateLabourgovernment
• Duplicationofservices/waste
Healthcaresystemtiers
• Primarycare:firstlevelofcontactwiththehealthsysteme.g.GP–noreferralisneeded.Dentists,
indigenoushealthworkers,pharmacists,physiotherapistsandchiropractorsfallunderthiscategory
• Secondarycare:referralfromprimarycaregivere.g.referralfromGPtoseeaspecialist.
Sonographers,echocardiographers,radiographers,radiologists,cardiologists,obstetricians,
urologistsandpaediatriciansfallunderthiscategory
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• Tertiarycare:typically,hospital–publicorprivate
Medicare
• Universalhealthcaresystemintroducedin1984
• Medicareisthefederalgovernmenthealthinsurancesystemmanagedbythe“departmentof
healthandaging”
• TheprincipalaimofMedicareistomakehealthcareaffordableandaccessibleforallAustralians
throughfreeofsubsidedhealthcare
• TheMedicareBenefitsSchedule(MBS)listsallservicesthatarecoveredunderMedicareinsurance
scheme
• ThePharmaceuticalBenefitsScheme(PBS)providessubsidisedfundingfornecessary
pharmaceuticals
• ReciprocalhealthcareagreementsenableAustralianstoreceivefreeessentialmedicaltreatment
whilstoverseasincertaincountries
• 3mainobjectives:fundmedicalservices,fundpharmaceuticalbenefitsandfundpublichospital
care
MedicareLevy
• Startedin1984
• Providesapproximately1/3ofMedicarefunding(remaindercomesfromgeneraltaxes)
• 2%oftaxableincomepaidbyindividualsearningaboveacertainthreshold
MedicareSurcharge
• AnadditionalsurchargeinadditiontotheMedicareLevythathighearningindividualspaythatdo
nothaveanappropriatelevelofprivatehealthcover
PharmaceuticalBenefitsScheme
• Startedin1948
• ThePBSisaschemethatsubsidisesthecostofmedicineforarangeofmedicalconditions
• ThePBSschedulelistsallthemedicinesavailabletopatientsatagovernmentsubsidisedprice
• AllindividualsthatholdacurrentMedicarecardareeligibleforPBS
• Co-paymentof$38.30formostPBSmedicines
• Patientsafetynetof$1,475.70perfamilyperannum
PrivateHealthInsurance
• StronglyencouragedbytheAustraliangovernment
• GovernmentoffersarebateforMedicarecardholderswhotakeoutprivatehealthinsurance
• Benefits:providesshorterwaitingtimes,morephysician/hospitalchoice,fundspartancillary
serviceslikedentistry,physiotherapy
MedicareandDiagnosticImaging
• Rebatesareprovidedforcertaindiagnosticimagingservices,butonlyto:practicesaccredited
undertheDiagnosticImagingAccreditationScheme(DIAS)
• DIASdevelopedtoensuresafetyandqualitystandardsfordiagnosticimagingpractices
• MRIunitsmustberegisteredforpatientstoreceiverebates
• UltrasoundinMBS:
- General:Group1Subgroup1Itemnumber55005-55855
- Echocardiography:Group1Subgroup2Itemnumber55113–
NHMRC
• NationalHealthandMedicalResearchCouncil
• Establishedin1926
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• Supportshealthandmedicalrelatedresearch
• Provideshealthadvicetohealthprofessionalsandgovernments,aswellasthegeneralcommunity
• Providesadviceonethicalbehaviour
5. MEDICALTERMINOLOGY
Themainsourcesofmedicalterminologyaredrawnfrommanylanguages.Greektermsareusedmainlyin
clinicalterminologyandLatintermsareusedmainlyinanatomicalterminology.
GreekoriginsofMedicalTerminology
• Greekswerefoundersofrationalmedicineinabout5thcenturyBC
• HippocraticSchool,andlaterGalenformulatedthetheorieswhichdominatedmedicineupuntil
beginning18thcentury
• Hippocraticsfirsttodescribediseasebasedonobservation
• DiagnosisandsurgerytermsaremainlyGreekinorigin
LatinOriginsofMedicalTerminology
• Latinwastheoriginaluniversallanguageofthewesternworld,andwasthelanguageofscienceup
tothebeginningofthe18thcentury.AllmedicaltextswerethereforewritteninLatin
• AndreasVesalius–Dehumanicorporisfabrica
• AnatomicaltermsarepredominantlyLatininorigin
ComponentsofMedicalWords
• Mostmedicalwordshavethreecomponents:prefix,rootandsuffix
• Root=oftenequalsanelementofanatomy
• Asuffixorprefixareaddedtomodifytherootwordandaddadditionalmeaning
• E.g.pericarditis:peri–around,card–heart,itis–inflammation
UltrasoundTerminology
• Echogenic–toproduceechoes.Structureswhicharemoreechogenicappear‘brighter’
• Hyperechoic(comparativeterm)–areawithincreasedechoes(appears‘brighter’onimage)
• Hypoechoic(comparativeterm)–areawithdecreasedechoes(appears‘darker’onimage)
• Isoechoic(comparativeterm)–areawithasimilarlevelofechoreturnonimage(similar
echogenicity)
• Anechoic/sonolucent–areawithnointernalechoes(appearsblackonimage)
• Homogenous–areawhichcontainsechoesofauniformcomposition
• Heterogeneous–areawhichcontainsechoesofvaryingcomposition
• Echotexture–descriptionoftheechopatternwithinastructuree.g.Homogeneous,echogenic
• Acousticwindow–anareaofthebodywhichisfreefromgasorbone,whichultrasoundcaneasily
passthrough.Theanatomicalstructuresdeeptothis‘window’canbemoreoptimallyevaluated.
Weusetheurinarybladderasanacousticwindowtoimagetheuterus.Weusetheliverasan
acousticwindowtoimagethekidney
• Attenuation–ultrasoundlosesenergyasittravelsthroughtissue.Fivemainprocessesof
attenuation:absorption,reflection,scattering,refractionanddivergence
• Artefacts–structureinanultrasoundimagewhichdoesnotcorrespondtoanactualstructure
withinthebody.Structureswhichareseeninanimagebutarenotactuallypresent,orstructures
whicharepresentandshouldbeseeninanimagebutarenot.Theyareanapparentechoforwhich
thedistance,directionoramplitudeoftheechodonotcorrespondtoarealtarget
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• Posteriorenhancement–anartefactduetoanover-amplificationofechoesdeeptoanareaoflow
attenuation,suchasafluid-filledarea
• Posteriorshadowing–anartefactcausedbyanareaoflowamplitudeofechoesdeeptoahighly
attenuatingstructure,suchasbone
• Adescriptionoftheouteredge/surfaceofananatomicalstructuremaybedescribedas:
encapsulated,welldefined/poorlydefined,lobulated/smooth/speculated,thickwalled/thinwalled
• PosteriorShadowing
• Cystic–usedtodescribeafluid-filledstructure.Doesnotcontaininternalechoesandexhibits
posteriorenhancement
Welldefined Poorlydefined Lobulated SpiculatedSmooth
Thick-walled Thin-walled Hyperechoic Hypoechoic Isoechoic
Anechoic Homogenous Heterogeneous AcousticWindow Posteriorenhancement
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• Loculated–fluidcollectionswhichareseparatedintocompartmentsbyseptations
• Septations–divisionswithinastructure.Variableappearancese.g.thick,thin,vascular
6. ULTRASOUNDSCANPLANES
TransducerOrientation
• Thinkabout:pathofinsonatingsoundandechoandnotchindicatorandtransducer
• Scanningplane:transducerorientationtoanatomicplaneoforgan
UltrasoundScanPlanes
• Longitudinal‘long’–thelongestlengthofthestructurebeingexamined(sagittalorcoronal)
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• Transverse/Axialplaneofstructurebeingexamined(90degreestoLong)
Longitudinal:Sagittalplanes–transducernotchalwaystowardspatientheadinsagittalplanes
Longitudinal:Coronalplanes–transducernotchalwaystowardspatientsheadincoronalplanes
Transverseplanesanteriorandposteriorsurfaces–transducernotchalwaystowardsyouintransverse
planes
Transverseplanesrightorleftsurfaces–transducernotchalwaystowardsyouintransverseplanes