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Be Your Own Advocate:
Understanding Ionizing Radiation and
Exposure from Medical Imaging
Joy Yvette Payne, PhD Student
Walden University
PUBH 8165-1
Dr. Robert Marino
Fall, 2011
Objectives
At the end of this presentation you will be able to:
• Converse about key points of ionizing radiation
• Describe the short and long-term health effects
associated with ionizing radiation
• Identify medical imaging procedures that may increase
exposure to ionizing radiation
• Advocate for self and family when medical imaging is
recommended
Introduction
Natural News. (2010). Use of high-radiation CT scans in emergency rooms triples over nine years. Retrieved October 20, 2011 from
http://www.naturalnews.com/030776_CT_scans_radiation.html New York Timers. (2010). Radiation, Risks Are Focus of Breast Screening
Study. Retrieved October 21, 2011 from http://www.nytimes.com/2010/08/24/science/24breast.html USA Today. (2010). Cancer risks
prompt doctors to try to lower imaging scan radiation. Retrieved October 21, 2011 from http://www.usatoday.com/news/health/2010-05-05radiation05_st_N.htm
Radiation Waves Penetration Power
Paper
Alpha
Beta
Foil
Concrete
Energy
Low
Medium
Gamma
U.S. Environmental Protection Agency (EPA). (2011e) . Why are some atoms Radioactive. Retrieved October 13, 2011 from
http://www.epa.gov/rpdweb00/understand/radiation.html
High
Common Radiation Units and Symbol
 Sievert (Sv)1 – unit of equivalent dose (international)
– 1 Sv = 100 rem (0.001 Sv = 1mSv)
 Rem1 - US unit of measurement
– Millirem (mrem) = 1/1000 of a rem
 Gray (Gy) 1 – unit of absorbed dose (international)
– Used to describe radiation treatment dose
 Rad1 – US unit of absorbed dose
– 1 Gy = 100 rad
Tri-foil2
1. U.S. Environmental Protection Agency (EPA). (2011a). Radiation Protection Basics. Retrieved October 7, 2011 from
http://www.epa.gov/radiation/understand/protection_basics.html 2..U. S. Environmental Protection Agency (EPA). (2011d). Radiation Protection. Radiation
Symbols. Retrieved October 7, 2011 from http://www.epa.gov/rpdweb00/understand/symbols.html
Exposure Limits and Averages
Annual Radiation Dose Limits
Agency
Radiation Worker - 5,000 mrem
NRC, "occupationally" exposed
General Public - 100 mrem
NRC, member of the public
General Public - 10 mrem
EPA, air pathway
General Public - 4 mrem
EPA, drinking water pathway
U.S. Environmental Protection Agency (EPA)
U.S. Nuclear Regulatory Commission (NRC)
Average Annual Dose
Natural Sources
310 mrem
Average Annual Dose
All Sources
620 mrem
U.S. Environmental Protection Agency (EPA). (2007). Radiation Risks and Realities. Retrieved October 7, 2011 from
http://epa.gov/radiation/docs/402-k-07-006.pdf U. S. Nuclear Regulatory Commission. (2011a). Fact Sheet on Biological Effects of Radiation.
Retrieved October 14, 2011 from http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html
Biological Effects of Radiation
Outcomes of living cells:
 Cells die and replace themselves (normal process)
 Cells repair themselves - no left-over damage
 Cells incorrectly repair themselves – biophysical changes
Doses around 1 Sievert (Sv) may lead to heart disease,
stroke, digestive disorders and respiratory disease.
The exact effects of the cumulative health effects of
exposure to ionizing radiation are difficult to determine.
U. S. Nuclear Regulatory Commission. (2011a). Fact Sheet on Biological Effects of Radiation. Retrieved October 10, 2011 from
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html
Health Effects Based on Acute Exposure
Exposure
(rem)
Health Effect
5-10
changes in blood chemistry
50
nausea
55
fatigue
70
vomiting
75
hair loss
90
diarrhea
100
hemorrhage
400
possible death
1,000
destruction of intestinal lining
internal bleeding and death
2,000
Time to Onset
(without treatment)
hours
2-3 weeks
within 2 months
1-2 weeks
damage to central nervous system
loss of consciousness; death
Minutes/hours to days
U.S. Environmental Protection Agency (EPA). (2011c). Radiation Protection. Health Effects. Retrieved October 1, 2011 from
http://epa.gov/radiation/understand/health_effects.html
Estimated Health Effects of Radiation
in Pregnancy
 Increased Cancer Risk
– Depends on amount of radiation and amount of time exposed
– If acute exposure = to 500 Chest X rays, increased risk about 2%
 Other health effects are unlikely when the dose to the fetus is very low
– During 1st two weeks of pregnancy – greatest concern is death
– Weeks 2-18 – birth defects, especially mental retardation
– If 1000 fetuses exposed to 1 rem radiation 1 to 4 would be born with mental retardation
– Week 18 to birth – unlikely effects, unless dose is very high
 Genetic mutations – both parents exposed to 1 rem of radiation
– In 1 million births, 50 severe hereditary effects expected
– Compared to 100,000 other cases of genetic defects
Centers for Disease Control and Protection (CDC). (2011). Emergency Preparedness and Response. Radiation and Pregnancy: A Fact Sheet.
Retrieved October 3, 2011 from http://www.bt.cdc.gov/radiation/prenatal.asp U. S. Nuclear Regulatory Commission. (2011a). Fact Sheet on
Biological Effects of Radiation. Retrieved October 10, 2011 from http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html
Estimated Health Effects of Exposure to
Ionizing Radiation – Lifetime Exposure
Cancer – increased risk of developing cancer with
increasing doses of radiation
 10,000 people exposed to 1 rem in small doses over
their lifetime
– 2000 non-radiation deaths expected (baseline)
– 5 or 6 radiation deaths would occur
– Indistinguishable from cancer from other causes
 Normal exposure to background radiation per year is 3/10
of a rem (300mrem)
 Cancers do not appear until many years after the
radiation has been received
U. S. Environmental Protection Agency (EPA). (2007). Radiation Risks and Realities. Retrieved October 7, 2011 from
http://epa.gov/radiation/docs/402-k-07-006.pdf
U.S. Nuclear Regulatory Commission. (2011b). Radiation Exposure and Cancer. Retrieved
October 3, 2011 from http://www.nrc.gov/about-nrc/radiation/health-effects/rad-exposure-cancer.html
Benefits / Uses of Radiation
 Some televisions and
computers
 Sterilization of hospital
supplies
 Smoke detectors
 Diagnostic imaging
 Power (illumination)
 Therapeutic
 Steel and paper factories
– Medicine
 Inspection
– Treatment (XRT)
– Security - Airport
– Welds – airplanes/boats
American Nuclear Association. (2008). Societal Benefits of Radiation Position Statement. Retrieved Oct 7, 2011 from
http://www.ans.org/pi/ps/docs/ps73.pdf
U.S. Population Exposed to Increased
Radiation
In March, 2009, the National Council on Radiation
Protection and Measurement released a critical
report that indicated that radiation dose to the
United States population had risen dramatically
since the early 1980’s.
Schauer, D. A. & Linton, O. W. (2009). National Council on Radiation Protection and Measurements Report shows substantial medical
exposure increase. Radiology, 253 (2), 293-296.
Sources of U.S. Radiation Exposure
U. S. Nuclear Regulatory Commission. (2011a). Fact Sheet on Biological Effects of Radiation. Retrieved October 10, 2011 from
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html
Medical Imaging Procedures / Examples
 Standard projection x-rays
– Chest, hip, dental x-rays,
– Mammogram
 CT scan (CAT Scan)
– Head, chest, abdomen
 Nuclear medicine procedures
– Angiogram
 Fluoroscopy
– Used in cardiac catherazation
U. S. Food and Drug Administration. (2010b). White Paper: Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging Retrieved
October 1, 2011 from http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
Radiation Doses of Medical Imaging Procedures
Procedure
Dose Range, mSv
Average Dose,
Chest X-ray
mSv
Equivalent Dose
X-rays
Chest
0.02-0.67
0.34
1
L-spine
0.8-2.4
1.6
4.7
Hip
0.3-0.6
0.4
1.1
Barium enema
7-9
8
23.5
Mammography
0.07-0.89
0.48
1.4
Upper GI tract
3.6
3.6
10.6
0.02-0.334
0.18
0.53
Thoracic
8.3-11.7
10
29.4
Abdomen
7.6-16
11.8
35
Pelvis
10-13
11.5
33.8
71.9
71.9
211.5
Dental
CT scans
Angiographs
Cardiac
Medscape Reference. (2011). Ionizing Radiation Exposure with Medical Imaging . Abbreviated from Table 4. Retrieved October 12, 2011 from
http://emedicine.medscape.com/article/1464228-overview
Public Health Concern
More
• Increased
Medical
Exposure
Procedures to Ionizing
Radiation
More
Ionizing
Radiation
More DNA
damage
More DNA
Damage
Increased
lifetime
cancer risk
Millions of exams performed each year
Estimates that 1 in 270 Women & 1 in 600 Men who undergo CT
coronary angiography at age 40 will develop cancer from that CT scan1
1. Smith-Bindman, R., Lipson, J., Marcus, R., Kim, K. P., Mahesh, M., & Gould, R. (2009). Radiation dose associated with common computed
tomography examinations and the associated lifetime attributable risk of cancer. Archives of Internal Medicine, 169(22), 2078-2086. 2. U. S. Food
and Drug Administration. (2010b). White Paper: Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging Retrieved October 1,
2011 from http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
Balance Risk and Benefits
 Some level of exposure is necessary
– Determine extent of injury
– Determine extent of disease
– Support diagnosis or treatment
 Exposure from medical procedures should not be feared –
but must be respected
 ALARA Principle – as low as reasonably achievable
 Risks reduction by decreasing unnecessary exposure
Medscape Reference. (2011). Ionizing Radiation Exposure with Medical Imaging . Retrieved October 12, 2011 from
http://emedicine.medscape.com/article/1464228-overview
Radiation Protection Principle
S
H
I
E
L
D
I
N
G
TIME
DISTANCE
U.S. Environmental Protection Agency (EPA). (2011a). Radiation Protection Basics. Retrieved October 7, 2011 from
http://www.epa.gov/radiation/understand/protection_basics.html
Safe Use of Medical Imaging Devices
Improved Quality
Assurance
Standardization
Safety
Training
U. S. Food and Drug Administration. (2010)b. White Paper: Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging Retrieved
October 1, 2011 from http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
FDA and Partners Initiative
Reduce Unnecessary Radiation Exposure from Medical
Imaging:
 Promote safe use of medical imaging devices
 Support informed clinical decision making
 Increase patient awareness
U. S. Food and Drug Administration. (2010b). White Paper: Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging Retrieved
October 1, 2011 from http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
Image Gently Campaign
 Primary Objective: raise awareness of the opportunities to
lower radiation dose in the imaging of children
 Ultimate Goal: change practice
 Strategy: straightforward information provided to
every member of the care team
http://www.imagewisely.org/
www.imagegently.org
The Alliance for Radiation Safety in Pediatric Imaging. (2011). Image Gently. Retrieved October 12, 2011 from
http://www.pedrad.org/associations/5364/ig/
Image Wisely. (2010b). Radiation Safety in Adult Medical Imaging. Retrieved October 15, 2011 from
http://www.imagewisely.org/2.
Informed Clinical Decision Making
FDA Actions / Recommendations
 Establish requirements for manufacturers of imaging
equipment to record radiation dose information for use in
patient charts or in a dose registry
 Recommend continued development of criteria for
appropriate medical imaging use
U. S. Food and Drug Administration. (2010b). White Paper: Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging Retrieved
October 1, 2011 from http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
American College of Radiology
Appropriateness Criteria
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_
criteria.aspx
 Diagnostic Imaging Topics
– Breast
– Cardiac
– Gastrointestinal
– Musculoskeletal
– Neurologic
– Pediatric
– Thoracic
– Vascular
– Women’s
 Interventional Radiology
Topics
 Radiation Oncology Topics
– Bone Metastases
– Brain Metastases
– Breast
– Gynecology
– Head & Neck
– Hodgkin’s Lymphoma
– Lung
– Prostate
– Rectal/Anal
American College of Radiology. (2011). ACR Appropriateness Criteria®. Retrieved October 7, 2011 from http://www.acr.org/ac.
Ask your doctor…
 Why do I need this exam?
 How will information from this exam improve my health?
 Are there others tests , as good, that do not use radiation?
Image Wisely. (2010a). Patients. Retrieved October 15, 2011 from http://www.imagewisely.org/Patients.aspx?CSRT=11519610464130392779
Increase Patient Awareness
 FDA collaboration with American College of Radiology and
Radiological Society of North America to develop medical
imaging card tool for tracking medical procedures
– Paper tracking
– Electronic tracking
 Radiation dose calculators
U. S. Food and Drug Administration. (2010b). White Paper: Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging Retrieved
October 1, 2011 from http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
My Medical Imaging History
U.S. Food and Drug Administration. (2010a). My Medical Imaging History. Retrieved October 11, 2011 from
http://www.fda.gov/downloads/Radiation-EmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
Calculate Your Radiation Dose
Open this hyperlink to the EPA website
http://epa.gov/radiation/understand/calculate.html
Source
Cosmic radiation at sea level (from outer space)
What is the elevation (in feet) of your town?
Your Average Annual Dose
(mrem)
26
Choose from dropdown
Terrestrial (from the ground):
What region of the US do you live in?
Internal radiation (in your body):
From food and water, (e.g., potassium)
From air, (radon)
Do you wear a plutonium powered pacemaker?
Do you have porcelain crowns or false teeth?
Choose from dropdown
EX; Gulf Coast Region
40
200
Choose from dropdown (Y/N)
Choose from dropdown (Y/N)
U.S. Environmental Protection Agency. (2011b). Radiation Protection. Calculate Your Radiation Dose. Retrieved Oct 1, 2011 from
http://epa.gov/radiation/understand/calculate.html
Know Your Risks and Advocate!
 48% of radiation exposure in the U.S. is from medical
procedures
 Cumulative exposure may lead to long term health
problems, especially cancer
 Document and share your medical imaging history with
your doctor
 Calculate and know your estimated annual radiation
exposure
 Discuss, with your doctor, the need for imaging or
alternatives that may be available
 Have a healthy respect for radiation; it provides great
benefit to our society
References
American College of Radiology. (2011). ACR Appropriateness Criteria®. Retrieved October 7,
2011 from
http://www.acr.org/ac.
American Nuclear Association. (2008). Societal Benefits of Radiation Position Statement.
Retrieved October 7, 2011 from http://www.ans.org/pi/ps/docs/ps73.pdf
Berrington de González, A. & Darby, S. (2004). Risk of cancer from diagnostic X-rays: Estimates
for the UK and 14 other countries. Lancet, 363, 345-51.
Centers for Disease Control and Protection (CDC). (2011). Emergency Preparedness and
Response. Radiation and Pregnancy: A Fact Sheet. Retrieved October 3, 2011 from
http://www.bt.cdc.gov/radiation/prenatal.asp
Health Physics Society. (2011). Radiation Basics. Retrieved October 9, 2011 from
http://www.hps.org/publicinformation/ate/faqs/radiation.htmlI
Image Wisely. (2010a). Patients. Retrieved October 15, 2011 from
http://www.imagewisely.org/Patients.aspx?CSRT=11519610464130392779
References
Image Wisely. (2010b). Radiation Safety in Adult Medical Imaging. Retrieved October 15, 2011
from http://www.imagewisely.org/
McCollough, C. H., Schuler, B. A., Atwell, T. D., Braun, N. N., Regner, D. M., Brown, D. L., &
LeRoy, A. J. (2007). Radiation Exposure and Pregnancy: When Should We Be Concerned?
Radiographics, 27, 909-917. doi: 10.1148/rg.274065149
Medscape Reference. (2011). Ionizing Radiation Exposure with Medical Imaging. Retrieved
October 12, 2011 from http://emedicine.medscape.com/article/1464228-overview
Natural News. (2010). Use of high-radiation CT scans in emergency rooms triples over nine
years. Retrieved October 20, 2011 from
http://www.naturalnews.com/030776_CT_scans_radiation.html
New York Timers. (2010). Radiation, Risks Are Focus of Breast Screening Study. Retrieved
October 21, 2011 from http://www.nytimes.com/2010/08/24/science/24breast.html
Schauer, D. A. & Linton, O. W. (2009). National Council on Radiation Protection and
Measurements Report shows substantial medical exposure increase. Radiology, 253 (2),
293-296.
References
Smith-Bindman, R., Lipson, J., Marcus, R., Kim, K. P., Mahesh, M., & Gould, R. (2009). Radiation
dose associated with common computed tomography examinations and the associated
lifetime attributable risk of cancer. Archives of Internal Medicine, 169(22), 2078-2086.
The Alliance for Radiation Safety in Pediatric Imaging. (2011). Image Gently. Retrieved October
12, 2011 from http://www.pedrad.org/associations/5364/ig/
USA Today. (2010). Cancer risks prompt doctors to try to lower imaging scan radiation. Retrieved
October 21, 2011 from http://www.usatoday.com/news/health/2010-05-05radiation05_st_N.htm
U. S. Environmental Protection Agency (EPA). (2007). Radiation Risks and Realities. Retrieved
October 7, 2011 from http://epa.gov/radiation/docs/402-k-07-006.pdf
U. S. Environmental Protection Agency (EPA). (2011a). Radiation Protection Basics. Retrieved
October 7, 2011 from http://www.epa.gov/radiation/understand/protection_basics.html
U.S. Environmental Protection Agency (EPA). (2011b). Radiation Protection. Calculate Your
Radiation Dose. Retrieved Oct 1, 2011 from
http://epa.gov/radiation/understand/calculate.html
References
U.S. Environmental Protection Agency (EPA). (2011c). Radiation Protection. Health Effects.
Retrieved October 1, 2011 from http://epa.gov/radiation/understand/health_effects.html
U. S. Environmental Protection Agency (EPA). (2011d). Radiation Protection. Radiation Symbols.
Retrieved October 7, 2011 from http://www.epa.gov/rpdweb00/understand/symbols.html
U. S. Environmental Protection Agency (EPA). (2011e) Why are some atoms Radioactive.
Retrieved October 13, 2011 from http://www.epa.gov/rpdweb00/understand/radiation.html
U.S. Food and Drug Administration. (2010a). My Medical Imaging History. Retrieved October 11,
2011 from http://www.fda.gov/downloads/RadiationEmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
U. S. Food and Drug Administration. (2010b). White Paper: Initiative to Reduce Unnecessary
Radiation Exposure from Medical Imaging Retrieved October 1, 2011 from
http://www.fda.gov/downloads/RadiationEmittingProducts/RadiationSafety/RadiationDoseReduction/UCM235128.pdf
U. S. Nuclear Regulatory Commission. (2011a). Fact Sheet on Biological Effects of Radiation.
Retrieved October 10, 2011 from http://www.nrc.gov/reading-rm/doc-collections/factsheets/bio-effects-radiation.htmlh
U.S. Nuclear Regulatory Commission. (2011b). Radiation Exposure and Cancer. Retrieved
October 3, 2011 from http://www.nrc.gov/about-nrc/radiation/health-effects/rad-exposurecancer.html
Additional Resources
American Academy of Pediatrics. (2009). Imaging and Medical Radiation Safety: Important
Information for Parents. Retrieved October 21, 2011 from
http://www.aap.org/sections/radiology/RadiologyParentPage.pdf
Furry Elephant. (n.d.). Lesson 5: How radiation harms. Retrieved October 21, 2011 from
http://www.furryelephant.com/content/radioactivity/nuclear-radiation-health-effects/
RadiologInfo.org. (2011). Patient Safety: Radiation Exposure in X-ray and CT Examinations.
Retrieved October 21, 2011 from
http://www.radiologyinfo.org/en/safety/index.cfm?pg=sfty_xray
U.S. Food and Drug Administration. (2009). FDA Makes Interim Recommendations to Address
Concern of Excess Radiation Exposure during CT Perfusion Imaging. Retrieved October 21,
2011 from
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2009/ucm193190.htm
U.S. Food and Drug Administration. (2010). Safety Investigation of CT Brain Perfusion Scans:
Update 11/9/2010. Retrieved October 21, 2010 from
http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm185898.htm
World Health Organization. (2011). Ionizing Radiation. Retrieved October 21, 2011 from
http://www.who.int/ionizing_radiation/about/what_is_ir/en/index.html