孕婦影像學(xué)課件

RadiationinPregnancySehraSampsonMS4OHSURadiationinPregnancySehraSa1FetalDevelopmentEmbryonicPeriod:firstdayoflastmenstrualperiodthroughthe9thweek,includesorganogenesisFetalPeriod:10thweekthroughbirthFetalDevelopmentEmbryonicPer2RadiationRadiationquantitiesandunitsThenewunitofdoseisthegray(Gy,1Gy=100rad).Indiagnosticradiology,dosesaresmallandaregenerallyexpressedinmillirads(1mrad=0.001rad)ormicrograys(1mGy=0.000001Gy).Whatisarad?theamountofenergydepositedperkilogramoftissueWhatistheusefulnessof“rads”?tocomparetheradiationdoseindifferentexposures.Naturalbackgroundexposureatsealevelisabout300mradperyear.RadiationRadiationquantities3RadiationandFetalDevelopmentThemaximallimitofionizingradiationtowhichthefetusshouldbeexposedduringpregnancyisacumulativedoseof5rad.

RadiationandFetalDevelopmen4RadiationandFetalDevelopment"[Fetal]riskisconsideredtobenegligibleat5radorlesswhencomparedtotheotherrisksofpregnancy,andtheriskofmalformationsissignificantlyincreasedabovecontrollevelsonlyatdosesabove15rad."--NationalCouncilonRadiationProtectionandMeasurements.Medicalradiationexposureofpregnantandpotentiallypregnantwomen.NCRPReportno.54.Bethesda,Md.:TheCouncil,1977.RadiationandFetalDevelopmen5ExposureCategories TeratogenesisorfetalmalformationCarcinogenesisorinducedmalignancyMutagenesisoralterationofgerm-linegenesExposureCategories Teratogene6Exposure–TeratogenesisThemostcommonfetalmalformationscausedbyhigh-doseradiationareofthecentralnervoussystem,primarilymicrocephalyandmentalretardation.

Onlyshownincaseswherefetuswasexposedto10-150rad,particularlybefore10weeksgestation.Exposure–TeratogenesisThemo7Exposure-TeratogenesisTheriskofbirthdefectssuchasmalformationofthelips,mid-face,teeth,orexternalgenitaliaaregreatestwithexposuresof5-25radsbetween3-10weeksgestation.Theriskofbirthdefectsormalformationsdecreasesconsiderablyafterthe10thweekofgestation.Exposure-TeratogenesisTheri8Exposure–CarcinogenesisExposuretoaslittleas1-2radhasbeenassociatedwithaslightincreaseinchildhoodmalignancies,especiallyleukemia.Incidenceofleukemiainexposedchildrenisabout5per10,000.Generalincidenceofchildhoodleukemiaisabout3.6per10,000

Exposure–CarcinogenesisExpos9Exposure–MutagenesisExposuretoradiationmayincreasethefrequencyofgerm-linemutationsthatoccurnaturallyinthegeneralpopulation.Theexposuredosagerequiredtodoublethisbaselinemutationrateisbetween50-100rad.Exposure–MutagenesisExposure10ImaginginPregnancyRadiatingproceduresX-RayCTScanNuclearMedicineFluoroscopyNon-radiatingproceduresMRIUltrasoundDiagnosticradiologicproceduresshouldnotbeperformedduringpregnancyunlesstheinformationtobegainedfromthestudyisnecessaryforthecareofthepatient.ImaginginPregnancyRadiating11X-rayimaging

Singlediagnosticproceduresdonotresultinradiationdosesthatwillbeharmfultothedevelopingembryoorfetus."Womenshouldbecounseledthatx-rayexposurefromasinglediagnosticproceduredoesnotresultinharmfulfetaleffects.Specifically,exposuretolessthan5radhasnotbeenassociatedwithanincreaseinfetalanomaliesorpregnancyloss."--AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995X-rayimaging

Singlediagnosti12CTScanConsideredasecondarytestgivenrisksofradiationexposuretofetusACOG(AmericanCollegeofObstetrics/Gynecology)Recommendationsifimagingisrequired:Chest/HeadCT:Safesincetotaldose<1radAbd/Pelvis:Safeifonlytobetestedonce:totaldose:3.5radPelvisonly:Safetotaldose<250mrad.CTScanConsideredasecondary13NuclearMedicineStudiesUseacceptedradiopharmaceuticalconceptusdoseKeepexposureofradionuclidestoaminimum.Certainradiopharmaceuticals,suchas131-Iand32-P,rapidlycrosstheplacenta.ChooseanalternativetestifappropriateMostradiopharmaceuticalswillbeexpressedinbreastmilk.Avoid131-Iinthenursingmother.NuclearMedicineStudiesUseac14FluoroscopyUseacceptedradiopharmaceuticalconceptusdoseMinimizeexposuretimetopatientandfetusespeciallyifstudyisinabdomenorpelvisFluoroscopyUseacceptedradiop15CommondiagnosticproceduresandassociatedradiationdoseKEVINS.TOPPENBERG,M.D.,D.ASHLEYHILL,M.D.,andDAVIDP.MILLER,M.S.SafetyofRadiographicImagingDuringPregnancy.AmericanFamilyPhysician.April1999Commondiagnosticproceduresa16MagneticResonanceImagingConsideredapreferentialtesttoCTtoavoidionizingradiationGadoliniumshouldbeavoidedduringthe1sttrimesterRapidsequenceMRimagingispreferredtoconventionalMRimagingbecauseofbrieferexposureStudiesshowefficacyinMRstudiesofrightsidedabdominalpain(cholecystitis,appendicitis)MagneticResonanceImagingCons17MagneticResonanceImaging"Althoughtherehavebeennodocumentedadversefetaleffectsreported,theNationalRadiologicalProtectionBoardarbitrarilyadvisesagainstitsuseinthefirsttrimester."--AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995MagneticResonanceImaging"Alt18UltrasoundImagingConsideredthepreferredimagingmodalityinpregnancySensitivityofstudydependsonpatientanatomyandoperatortechniqueUltrasoundImagingConsideredt19UltrasoundImaging"Therehavebeennoreportsofdocumentedadversefetaleffectsfordiagnosticultrasoundprocedures,includingduplexDopplerimaging.""Therearenocontraindicationstoultrasoundproceduresduringpregnancy,andthismodalityhaslargelyreplacedx-rayastheprimarymethodoffetalimagingduringpregnancy."--AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995UltrasoundImaging"Therehave20PatientCounseling

TheAmericanCollegeofObstetriciansandGynecologistshasstatedthatexposuretoX-raysduringapregnancyisnotanindicationfortherapeuticabortion.Riskforteratogenesisandcarcinogenesisinthegeneralpopulationisapproximately286per1,000deliveries.Exposureof0.5radtoafetusadds,tothegeneralrisk,about0.17casesper1,000deliveries.PatientCounselingTheAmerica21PatientCounselingNursingmothers:Breastfeedingmustbeterminatedduringtreatmentwith131-I.Forallotherradiopharmaceuticals,theruleofthumbisto“pumpanddump”for24hoursafterexposure.Limitphysicalexposuretochildduringandshortlyafterexposuretomother.PatientCounselingNursingmoth22PatientCounselingAlthoughdiagnosticproceduresareverylowrisktothefetus,itisimportantnevertopromisetheparentsa“perfectbaby”.Whenadiagnosticstudyisneededformanagementofapregnantwoman,theAmericanCollegeofRadiologyrecommendsthathealthcareworkersshouldtellpatientsthatx-raysaresafeandprovidepatientswithaclearexplanationofthebenefitsoftheexamregardingtheircare.PatientCounselingAlthoughdia23ConclusionMaximallimitofionizingradiationtowhichthefetusshouldbeexposedduringpregnancyisacumulativedoseof5rad.Ifapregnantwomanneedsimaging,mostsinglediagnosticproceduresarelessthan1rad.Afewsinglestudiesarebetween1-5rads.Itisadvisabletoavoidexposurewhenpossible,useultrasoundorMRIwhenequivalentdatacanbeobtained.

ConclusionMaximallimitofion24ReferencesNationalCouncilonRadiationProtectionandMeasurements.Medicalradiationexposureofpregnantandpotentiallypregnantwomen.NCRPReportno.54.Bethesda,Md.:TheCouncil,1977.NationalCouncilonRadiationProtectionandMeasurements.Considerationsregardingtheunintendedradiationexposureoftheembryo,fetusornursingchild.NCRPCommentaryno9.Bethesda,Md.:TheCouncil,1994.AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995ToppenbergKS,HillA,MillerDP.SafetyofRadiographicImagingDuringPregnancy.AmericanFamilyPhysician.April1999El-KhouryGY,MadsenMT,BlakeME,YankowitzJ.ANewPregnancyPolicyforaNewEra.AJR.Feb2003Miller,JC.RisksfromIonizingRadiationinPregnancy.RadiologyRounds:ANewsletteforReferringPhysiciansMGHDept.ofRadiology.Feb2004.WagnerLK,LesterRG,SaldanaLR.ExposureofthePregnantPatienttoDiagnosticRadiations:Aguidetomedicalmanagement(2ndedition).MedicalPhysicsPublishing.1997.ReferencesNationalCouncilon25RadiationinPregnancySehraSampsonMS4OHSURadiationinPregnancySehraSa26FetalDevelopmentEmbryonicPeriod:firstdayoflastmenstrualperiodthroughthe9thweek,includesorganogenesisFetalPeriod:10thweekthroughbirthFetalDevelopmentEmbryonicPer27RadiationRadiationquantitiesandunitsThenewunitofdoseisthegray(Gy,1Gy=100rad).Indiagnosticradiology,dosesaresmallandaregenerallyexpressedinmillirads(1mrad=0.001rad)ormicrograys(1mGy=0.000001Gy).Whatisarad?theamountofenergydepositedperkilogramoftissueWhatistheusefulnessof“rads”?tocomparetheradiationdoseindifferentexposures.Naturalbackgroundexposureatsealevelisabout300mradperyear.RadiationRadiationquantities28RadiationandFetalDevelopmentThemaximallimitofionizingradiationtowhichthefetusshouldbeexposedduringpregnancyisacumulativedoseof5rad.

RadiationandFetalDevelopmen29RadiationandFetalDevelopment"[Fetal]riskisconsideredtobenegligibleat5radorlesswhencomparedtotheotherrisksofpregnancy,andtheriskofmalformationsissignificantlyincreasedabovecontrollevelsonlyatdosesabove15rad."--NationalCouncilonRadiationProtectionandMeasurements.Medicalradiationexposureofpregnantandpotentiallypregnantwomen.NCRPReportno.54.Bethesda,Md.:TheCouncil,1977.RadiationandFetalDevelopmen30ExposureCategories TeratogenesisorfetalmalformationCarcinogenesisorinducedmalignancyMutagenesisoralterationofgerm-linegenesExposureCategories Teratogene31Exposure–TeratogenesisThemostcommonfetalmalformationscausedbyhigh-doseradiationareofthecentralnervoussystem,primarilymicrocephalyandmentalretardation.

Onlyshownincaseswherefetuswasexposedto10-150rad,particularlybefore10weeksgestation.Exposure–TeratogenesisThemo32Exposure-TeratogenesisTheriskofbirthdefectssuchasmalformationofthelips,mid-face,teeth,orexternalgenitaliaaregreatestwithexposuresof5-25radsbetween3-10weeksgestation.Theriskofbirthdefectsormalformationsdecreasesconsiderablyafterthe10thweekofgestation.Exposure-TeratogenesisTheri33Exposure–CarcinogenesisExposuretoaslittleas1-2radhasbeenassociatedwithaslightincreaseinchildhoodmalignancies,especiallyleukemia.Incidenceofleukemiainexposedchildrenisabout5per10,000.Generalincidenceofchildhoodleukemiaisabout3.6per10,000

Exposure–CarcinogenesisExpos34Exposure–MutagenesisExposuretoradiationmayincreasethefrequencyofgerm-linemutationsthatoccurnaturallyinthegeneralpopulation.Theexposuredosagerequiredtodoublethisbaselinemutationrateisbetween50-100rad.Exposure–MutagenesisExposure35ImaginginPregnancyRadiatingproceduresX-RayCTScanNuclearMedicineFluoroscopyNon-radiatingproceduresMRIUltrasoundDiagnosticradiologicproceduresshouldnotbeperformedduringpregnancyunlesstheinformationtobegainedfromthestudyisnecessaryforthecareofthepatient.ImaginginPregnancyRadiating36X-rayimaging

Singlediagnosticproceduresdonotresultinradiationdosesthatwillbeharmfultothedevelopingembryoorfetus."Womenshouldbecounseledthatx-rayexposurefromasinglediagnosticproceduredoesnotresultinharmfulfetaleffects.Specifically,exposuretolessthan5radhasnotbeenassociatedwithanincreaseinfetalanomaliesorpregnancyloss."--AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995X-rayimaging

Singlediagnosti37CTScanConsideredasecondarytestgivenrisksofradiationexposuretofetusACOG(AmericanCollegeofObstetrics/Gynecology)Recommendationsifimagingisrequired:Chest/HeadCT:Safesincetotaldose<1radAbd/Pelvis:Safeifonlytobetestedonce:totaldose:3.5radPelvisonly:Safetotaldose<250mrad.CTScanConsideredasecondary38NuclearMedicineStudiesUseacceptedradiopharmaceuticalconceptusdoseKeepexposureofradionuclidestoaminimum.Certainradiopharmaceuticals,suchas131-Iand32-P,rapidlycrosstheplacenta.ChooseanalternativetestifappropriateMostradiopharmaceuticalswillbeexpressedinbreastmilk.Avoid131-Iinthenursingmother.NuclearMedicineStudiesUseac39FluoroscopyUseacceptedradiopharmaceuticalconceptusdoseMinimizeexposuretimetopatientandfetusespeciallyifstudyisinabdomenorpelvisFluoroscopyUseacceptedradiop40CommondiagnosticproceduresandassociatedradiationdoseKEVINS.TOPPENBERG,M.D.,D.ASHLEYHILL,M.D.,andDAVIDP.MILLER,M.S.SafetyofRadiographicImagingDuringPregnancy.AmericanFamilyPhysician.April1999Commondiagnosticproceduresa41MagneticResonanceImagingConsideredapreferentialtesttoCTtoavoidionizingradiationGadoliniumshouldbeavoidedduringthe1sttrimesterRapidsequenceMRimagingispreferredtoconventionalMRimagingbecauseofbrieferexposureStudiesshowefficacyinMRstudiesofrightsidedabdominalpain(cholecystitis,appendicitis)MagneticResonanceImagingCons42MagneticResonanceImaging"Althoughtherehavebeennodocumentedadversefetaleffectsreported,theNationalRadiologicalProtectionBoardarbitrarilyadvisesagainstitsuseinthefirsttrimester."--AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995MagneticResonanceImaging"Alt43UltrasoundImagingConsideredthepreferredimagingmodalityinpregnancySensitivityofstudydependsonpatientanatomyandoperatortechniqueUltrasoundImagingConsideredt44UltrasoundImaging"Therehavebeennoreportsofdocumentedadversefetaleffectsfordiagnosticultrasoundprocedures,includingduplexDopplerimaging.""Therearenocontraindicationstoultrasoundproceduresduringpregnancy,andthismodalityhaslargelyreplacedx-rayastheprimarymethodoffetalimagingduringpregnancy."--AmericanCollegeofObstetriciansandGynecologists,CommitteeonObstetricPractice.Guidelinesfordiagnosticimagingduringpregnancy.ACOGCommitteeopinionno.158.Washington,D.C.:ACOG,1995UltrasoundImaging"Therehave45PatientCounseling

TheAmericanCollegeofObstetriciansandGynecologistshasstatedthatexposuretoX-raysduringapregnancyisnotanindicationfortherapeuticabortion.Riskforteratogenesisandcarcinogenesisinthegeneralpopulationisapproximately286per1,000deliveries.Exposureof0.5radtoafetusadds,tothegeneralrisk,about0.17casesper1,000deliveries.PatientCounselingTheAmerica46PatientCounselingNursingmothers:Breastfeedingmustbeterminatedduringtreatmentwith131-I.Forallotherradiopharmaceuticals,theruleofthumbisto“pumpanddump”for24hoursafterexposure.Limitphysicalexposuretochildduringandshortlyafterexposuretomother.PatientCounselingNursingmoth47PatientCounselingAlthoughdiagnosticproceduresareverylowrisktothefetus,itisimportantnevertopromisetheparentsa“perfectbaby”.Whenadiagnosticstudyisneededformanagementofa