This presentation was recently given by Dr. Brett Heilbron on the CanadianEMR - Technology in Clinical Practice Cruise Conference - April 2013. Learning objectives for the session were to understand the risks associated with ionizing radiation, identify ways to optimize patient benefit and minimize risk and to discuss some of the controversies around medical imaging radiation. The presentation focuses on the use of a common technology in clinical settings - medical diagnostic imaging - and provides some guidance regarding this controversial topic.
7 steps How to prevent Thalassemia : Dr Sharda Jain & Vandana Gupta
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Radiation in Medical Diagnostic Imaging
1. Radiation in Medical DiagnosticRadiation in Medical Diagnostic
ImagingImaging
Brett Heilbron
Co-Director Advanced Cardiac
Imaging
Division of Cardiology
St. Paulās Hospital / UBC
3. Learning ObjectivesLearning Objectives
ļ¬ Understand the risks associated withUnderstand the risks associated with
ionizing radiationionizing radiation
ļ¬ Identify ways to optimize patient benefitIdentify ways to optimize patient benefit
and minimize riskand minimize risk
ļ¬ Discuss some of the controversies aroundDiscuss some of the controversies around
medical imaging radiationmedical imaging radiation
4. IntroductionIntroduction
ļ¬ Radiation sources and terminologyRadiation sources and terminology
ļ¬ Radiation health risk dataRadiation health risk data
ļ¬ Radiation dose reduction techniquesRadiation dose reduction techniques
ļ¬ The futureThe future
8. Radiation Terminology
Physical
Equivalent
Parameter Unit
Radiation
Exposure
No. of ions in air
produced by
photons
CTDI100 Coulomb (C) /kg
Radiation Dose Radiation energy
adsorbed at point
in pt.ās body
CTDIvol Gray (Gy)
Cumulative
Radiation
Exposure
Total radiation
energy adsorbed
by patientās body
DLP Gy x cm
Effective Radiation
Dose
Biological effect of
radiation dose
received
E Sievert (Sv)
9. Effective Dose
E = DLP x 0.014 mSv x mGy-1
x cm-1
ā¢ Derived from phantom scanning by vendor
ā¢ Assumes entire chest was imaged
ā¢ Assumes āstandardā organ sizes
ā¢ Assumes same anatomy for men & women
ā¢ Uses organ sensitivity assumptions subject to change
ā¢ Assumes risk independent of age
32. Chest radiographs ā 2 views 0.06 mSv (5)
Natural Background (Annual) 3-7 mSv (1,4)
Nuclear
Tc-99m (rest+stress) (MIBI) 9 ā 18 mSv (1,2)
Tl-201 (rest+stress) ~34 mSv (1,2)
Cardiac Catheterization 2-14 mSv
CCTA
Calcium Scoring 1-2 mSv
Prospective pulse / high-pitch spiral 0.5-4 mSv
Radiation Dose Comparison
(1) Society of Nuclear MediPulse Procedure Guideline for Myocardial Perfusion Imaging:
http://interactive.snm.org/index.cfm?PageID=1110&RPID=780&FileID=1302
(2) US Nuclear Regulatory Commission, Radiation Dose Estimates for Radiopharmaceuticals:
http://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6345/cr6345.pdf
(4) Journal of the American College of Cardiology, Vol. 47, No. 9, 2006. Radiation Exposure of Computed and Direct Intracoronary
Angiography.
(5) Committee to Assess Health risks from Low Levels of Ionizing Radiation, National Research Council, 2005.
33. Have you ever noticed that anyone
driving slower than you is an idiot and
anyone driving faster is a maniac?
George Carlin
34. Radiation Dose IssuesRadiation Dose Issues
Fully diagnostic image quality is the primary goal - ALARAFully diagnostic image quality is the primary goal - ALARA
Balance radiation risks against benefits ofBalance radiation risks against benefits of
diagnosis & risk of misdiagnosisdiagnosis & risk of misdiagnosis
Radiation dose estimates are impreciseRadiation dose estimates are imprecise
Uncertainty of risks of low-level radiationUncertainty of risks of low-level radiation
Radiation dose discussion is here to stayRadiation dose discussion is here to stay
35. Learning ObjectivesLearning Objectives
ļ¬ Understand the risks associated withUnderstand the risks associated with
ionizing radiationionizing radiation
ļ¬ Identify ways to optimize patient benefitIdentify ways to optimize patient benefit
and minimize riskand minimize risk
ļ¬ Discuss some of the controversies aroundDiscuss some of the controversies around
medical imaging radiationmedical imaging radiation
American Heart Association. Heart Disease and Stroke Statisticsā2004 Update . Dallas, Tex: American Heart Association; 2003. Feinberg WM, Blackshear JL, Laupacis A, Kronmal R, Hart RG. Prevalence, age distribution, and gender of patients with atrial fibrillation. Arch Intern Med . 1995;155:469-473. Waktare JEP, Camm AJ. Acute treatment of atrial fibrillation: why and when to maintain sinus rhythm. Am J Cardiol . 1998;81:3C-15C. Atrial fibrillation (AF) is one of the deadliest arrhythmias in the United States. According to the Heart Disease and Stroke Statistics ā Update 2004 published by the American Heart Association (AHA), 71,000 people die per year from AF or atrial flutter (AFl). AF is highly prevalent in the United States, affecting approximately 2 million people nationwide. The median age of AF patients is 75 years, with a prevalence of 2.3% in people older than 40 years and 5.9% in those over age 65. Approximately 70% of individuals with AF are between 65 and 85 years of age. Because the incidence of AF increases with age, its prevalence is increasingly proportionate to the rise in the elderly US population. In addition, AF is often associated with risk of stroke. Approximately 15% to 20% of strokes occur in patients with AF. AF is the cause of 416,000 hospitalizations per year, the most common arrhythmia requiring hospitalization. The high rate of hospitalization of individuals with AF reflects that this arrhythmia is associated with stroke, heart failure (HF), and death. Only 14% of patients with AF and 55% with paroxysmal AF show no demonstrable cardiac disease. AF also has a significant negative impact on exercise capacity and overall quality of life. AF Forum: Management, Anticoagulation, and Stroke Prevention Slide 2
American Heart Association. Heart Disease and Stroke Statisticsā2004 Update . Dallas, Tex: American Heart Association; 2003. Feinberg WM, Blackshear JL, Laupacis A, Kronmal R, Hart RG. Prevalence, age distribution, and gender of patients with atrial fibrillation. Arch Intern Med . 1995;155:469-473. Waktare JEP, Camm AJ. Acute treatment of atrial fibrillation: why and when to maintain sinus rhythm. Am J Cardiol . 1998;81:3C-15C. Atrial fibrillation (AF) is one of the deadliest arrhythmias in the United States. According to the Heart Disease and Stroke Statistics ā Update 2004 published by the American Heart Association (AHA), 71,000 people die per year from AF or atrial flutter (AFl). AF is highly prevalent in the United States, affecting approximately 2 million people nationwide. The median age of AF patients is 75 years, with a prevalence of 2.3% in people older than 40 years and 5.9% in those over age 65. Approximately 70% of individuals with AF are between 65 and 85 years of age. Because the incidence of AF increases with age, its prevalence is increasingly proportionate to the rise in the elderly US population. In addition, AF is often associated with risk of stroke. Approximately 15% to 20% of strokes occur in patients with AF. AF is the cause of 416,000 hospitalizations per year, the most common arrhythmia requiring hospitalization. The high rate of hospitalization of individuals with AF reflects that this arrhythmia is associated with stroke, heart failure (HF), and death. Only 14% of patients with AF and 55% with paroxysmal AF show no demonstrable cardiac disease. AF also has a significant negative impact on exercise capacity and overall quality of life. AF Forum: Management, Anticoagulation, and Stroke Prevention Slide 2