8/3/2010 1 Stewart Carlyle Bushong, Sc.D. Baylor College of Medicine Houston, Texas [email protected] …because one size does not fit all Stewart Carlyle Bushong, Sc.D. Baylor College of Medicine Houston, Texas [email protected]
Bushong, Stewart - ahra.org fileStewart Carlyle Bushong, Sc.D. Baylor College of Medicine Houston, Texas [email protected] …because one size does not fit all Stewart Carlyle Bushong,
May 16, 2018
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Stewart Carlyle Bushong, Sc.D.Baylor College of Medicine
Houston, [email protected]
…because one size does not fit all
Stewart Carlyle Bushong, Sc.D.Baylor College of Medicine
Houston, [email protected]
8/3/2010
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ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/Stochastic Imaging Modalities (R&F, CT, DR)Imaging Economics
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ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/Stochastic Imaging Modalities (R&F, CT, DR)Imaging Economics
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…because one size does not fit allThe Alliance for Radiation
Safety in Pediatric Imaging13 societies with representation from radiology, pediatrics, and medical physicsThe risk of death from cancer is about 1 in 5The risk is cumulative; each CT increases risk by 1/1000
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ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/Stochastic Imaging Modalities (R&F, CT, DR)Imaging Economics
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Radiation UnitsExposure……….. mR …… mGyTissue Dose………mrad…...mGyEff ti D SEffective Dose… mrem…..mSv
Resp
onse
Dose
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Resp
onse
BB
DoseDeterministic
Stochastic
NaturalIncidence
20%
0%
DeterministicNon-LinearThresholdS it i ith dSeverity increases with dose
StochasticLinearNon-ThresholdI id i ith dIncidence increases with dose
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Resp
onse
BB
DoseDeterministic
Stochastic
20%
0%
NaturalIncidence
Resp
onse
BB
DoseDeterministic
Stochastic
20%
0%50mSv
NaturalIncidence
Resp
onse
BB
DoseDeterministic
Stochastic
20%
0%50mSv
NaturalIncidence
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Resp
onse
BB
LymphocyteDepression
DoseDeterministic
Stochastic
20%
0%50mSv 100mSv
NaturalIncidence
Resp
onse
BB
LymphocyteDepression Local
TissueEffects
DoseDeterministic
Stochastic
20%
0%50mSv 100mSv 1000mSv
NaturalIncidence
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Resp
onse
BB
LymphocyteDepression Local
TissueEffects
DoseDeterministic
Stochastic
20%
0%50mSv 100mSv
DeterministicEffects
1000mSv
NaturalIncidence
Resp
onse
BB
LymphocyteDepression Local
TissueEffects
StochasticEffects
DoseDeterministic
Stochastic
20%
0%50mSv 100mSv
DeterministicEffects
1000mSv
NaturalIncidence
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Resp
onse
BB
LymphocyteDepression Local
TissueEffects
StochasticEffects
Hormesis
DoseDeterministic
Stochastic
20%
0%50mSv 100mSv
DeterministicEffects
1000mSv
Hormesis
NaturalIncidence
Resp
onse
BB
LymphocyteDepression Local
TissueEffects
StochasticEffects
Hormesisdi l
DoseDeterministic
Stochastic
20%
0%50mSv 100mSv
DeterministicEffects
1000mSv
o es sMedical imaging
NaturalIncidence
ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/Stochastic Imaging Modalities (R&F, CT, DR)Imaging Economics
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ALARAAt Last Another Raise AlreadyAny Little Annoyance Requires AttentionAfter Love in the Afternoon Repeat AgainAfter Love in the Afternoon Repeat AgainAs Long as Repeating AllowsAs Low As Reasonably Achievable
Cardinal PrinciplesTimeDistanceShieldingShielding
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More Is Not Often Better…
When CT is the right exam:Child size the kVp and mAOne scan (single phase) is often enoughScan only the indicated area
ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/StochasticImaging Modalities (R&F, CT, DR)Imaging Economics
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DeterministicNon-LinearThresholdS it i ith dSeverity increases with dose
StochasticLinearNon-ThresholdI id i ith dIncidence increases with dose
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ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/Stochastic Imaging Modalities (R&F, CT, DR)Imaging Economics
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Frush – Strategies for Dose Reduction
Consider other modality: MRI, USLimit IV contrast phasesLimit scan rangeLimit scan rangeReduce mAReduce kVpMinimize use of pitch <1.0Consider shielding: thyroid, breast, gonadsUse tube current modulation
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Effective Dose
Radiography ….. 0.1 mSvNuclear Medicine ….. 1 mSv
Fluoroscopy ….. 5 mSvComputed Tomography ….. 10 mSv
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Inflation……………….3%/yr
Healthcare…………....9%/yr
Medical Imaging........18%/yr
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ObjectivesRadiation Sources and IntensityRadiation Dose-Response RelationshipsALARA C di l P i i lALARA – Cardinal PrinciplesDeterministic/Stochastic Imaging Modalities (R&F, CT, DR)Imaging Economics
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