Dose and Radiation Risk in Pediatric CT

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  • This brings us to CT scanning
  • Institute of Medicine paper
  • CT scanning provides great benefit to our patients. If we agree on this, our task is to provide this benefit while reducing the risk as far as possible. No brainer is US slang for a decision that is very obvious, one that does not require thought.
  • This is the plan for this presentation
  • Even with slices every 5mm in young children the dose is decreased by over 75% by decreasing technique
  • 6 year old presented with a cavitary lesion
  • 1 month follow up CXR showed residual cavity
  • CT and CXR showed no lower lung disease, so we don’t need to scan the rest of the lung. If we miss the extreme apices, we’ll still cover what we need to. We’ll come back to this case to see if we can do even better to reduce radiation dose
  • CT and CXR showed no lower lung disease, so we don’t need to scan the rest of the lung. If we miss the extreme apices, we’ll still cover what we need to. We’ll come back to this case to see if we can do even better to reduce radiation dose
  • Evaluating practice allows opportunities to reduce dose
  • Again, we’ll come back to this situation
  • Again, we’ll come back to this situation
  • Previously discussed case
  • CXR showed little change. No CT planned for months, until CXR shows no residual or if clinical situation changes.
  • Again we can reduce radiation dose by not doing a CT scan
  • In addition to institutional guidelines there are many published guidelines from around the world that can be used as a starting point to developing protocols that reduce dose.
  • Dose and Radiation Risk in Pediatric CT

    1. 1. Understanding Radiation Risk from Diagnostic Imaging Wednesday, July 23, 2008 12:00 – 1:00 p.m. EDT © American Academy of Pediatrics 2008
    2. 2. Moderator: Marlene R. Miller, MD, MSc, FAAP Vice President, Quality - NACHRI Director of Quality and Safety & Associate Professor Johns Hopkins Children’s Centers Baltimore, Maryland
    3. 3. DISCLOSURES Financial Relationships One individual involved in this webinar: Melissa A. Singleton, M.Ed., Project Manager-Consultant has disclosed a financial relationship with an entity producing, marketing, re-selling, or distributing health care goods or services consumed by, or used on, patients. Her husband is employed by Walgreen Co. as a Workforce Administration Manager (technology position) for the company’s call centers. The AAP determined that this financial relationship does not relate to the educational assignment. None of the other involved individuals (Speakers, Moderators, Project Advisory Committee members, or Staff) has disclosed a relevant financial relationship. Refer to full AAP Disclosure Policy & Grid available below for download.
    4. 4. DISCLOSURES Off-Label/Investigational Uses None of the individuals (Speakers, Moderators, Project Advisory Committee members, or Staff) has disclosed that they intend to discuss or demonstrate pharmaceuticals and/or medical devices that are not approved. Refer to full AAP Disclosure Policy & Grid available below for download.
    5. 5. This activity was funded through an educational grant from the Physicians’ Foundation for Health Systems Excellence.
    6. 6. Visit our website: http://www.aap.org/saferhealthcare Resources: Useful strategies, valuable information links, and expert advice on reducing or eliminating medical errors affecting children. Webinars: Register for an upcoming, live Webinar, and earn a maximum of 1.0 AMA PRA Category 1 Credit™. Or, access a full archive, including audio, from one of the past Webinar offerings. Or, download just the Podcast or slide set from an archive. Latest News: Links to recent articles relating to pediatric patient safety. Email List: An e-community dedicated to pediatric patient safety issues and information exchange with other clinicians. Parents’ Corner: Resources to help parents understand what they can do to help ensure their optimal safety in the health care that their child receives.
    7. 7. CME CREDIT Live Webinar Only The American Academy of Pediatrics (AAP) is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.   The AAP designates this educational activity for a maximum of 1.0 AMA PRA Category 1 Credit™. Physicians should only claim credit commensurate with the extent of their participation in the activity.   This activity is acceptable for up to 1.0 AAP credits. These credits can be applied toward the AAP CME/CPD Award available to Fellows and Candidate Members of the American Academy of Pediatrics.
    8. 8. OTHER CREDIT Live Webinar Only This program is approved for 1.0 NAPNAP contact hours of which 0.0 contain pharmacology (Rx) content per the National Association of Pediatric Nurse Practitioners Continuing Education Guidelines.   The American Academy of Physician Assistants accepts AMA PRA Category 1 Credit(s)TM from organizations accredited by the ACCME. Important Note: You must have been pre-registered for this webinar in order to claim CME or other credit for your participation.
    9. 9. Speaker: Alan S. Brody, MD, FAAP Professor of Clinical Radiology and Pediatrics Division Chief of Thoracic Imaging Associate Director of Radiology Research, IRC Cincinnati Children’s Hospital Medical Center Cincinnati, Ohio
    10. 10. LEARNING OBJECTIVES Upon completion of the webinar, participants will be able to:  Discuss the radiation risk from CT scanning with patients and families.  Compare the amount of radiation from different ionizing radiation exposures.  List methods that should be used to limit radiation exposure from CT scanning.
    11. 11. UnderstandingUnderstanding Radiation Risk FromRadiation Risk From Diagnostic ImagingDiagnostic Imaging Alan S. Brody, MDAlan S. Brody, MD Professor of Radiology and PediatricsProfessor of Radiology and Pediatrics Chief, Thoracic ImagingChief, Thoracic Imaging Cincinnati Children’s HospitalCincinnati Children’s Hospital
    12. 12. DisclosuresDisclosures  I have no financial disclosuresI have no financial disclosures
    13. 13. DisclosuresDisclosures  I have no financial disclosuresI have no financial disclosures butbut
    14. 14. DisclosuresDisclosures  I have no financial disclosuresI have no financial disclosures butbut  I use CT scanning in my clinicalI use CT scanning in my clinical practicepractice  My research interests include CTMy research interests include CT scanning in cystic fibrosis andscanning in cystic fibrosis and interstitial lung diseaseinterstitial lung disease
    15. 15. OverviewOverview  Radiation risk from diagnosticRadiation risk from diagnostic imagingimaging  Benefits of diagnostic imagingBenefits of diagnostic imaging  Maximizing the benefit/risk ratioMaximizing the benefit/risk ratio  Discussing risk with patients andDiscussing risk with patients and familiesfamilies
    16. 16. Why the RecentWhy the Recent Concern?Concern?
    17. 17. Increasing CT ScansIncreasing CT Scans  CT scanning is almost universallyCT scanning is almost universally availableavailable  The number of CT scans is increasingThe number of CT scans is increasing every yearevery year  Indications for CT use are increasing,Indications for CT use are increasing, and may not consider possible risksand may not consider possible risks
    18. 18. New Risk InformationNew Risk Information  Low dose radiation risk estimatesLow dose radiation risk estimates from atomic bomb data are nowfrom atomic bomb data are now available for radiation dose levelsavailable for radiation dose levels similar to the radiation dose fromsimilar to the radiation dose from one CT scanone CT scan
    19. 19. One Paper Started it AllOne Paper Started it All  Estimating Risks of Radiation-Estimating Risks of Radiation- Induced Fatal Cancer fromInduced Fatal Cancer from Pediatric CTPediatric CT – David J. BrennerDavid J. Brenner – Carl D. EllistonCarl D. Elliston – Eric J. HallEric J. Hall – Walter E. BerdonWalter E. Berdon AJR 2001:176:289-296AJR 2001:176:289-296
    20. 20. CT Scans in Children Linked ToCT Scans in Children Linked To Cancer LaterCancer Later  ““Each year about 1.6 million childrenEach year about 1.6 million children in the USA get CT scans to the headin the USA get CT scans to the head and abdomen -- and about 1,500 ofand abdomen -- and about 1,500 of those will die later in life fromthose will die later in life from radiation-induced cancer”radiation-induced cancer”  Steve Sternberg, front page, USASteve Sternberg, front page, USA Today, January 22, 2001Today, January 22, 2001
    21. 21. American Journal ofAmerican Journal of Roentgenology February, 2001Roentgenology February, 2001  One CT scan carries a 1 in 1000One CT scan carries a 1 in 1000 risk of a fatal cancerrisk of a fatal cancer – Brenner, et al.Brenner, et al.  CT dose for children is often higherCT dose for children is often higher than necessarythan necessary – Patterson, et al.Patterson, et al.  Simple methods can decrease CTSimple methods can decrease CT dose for childrendose for children – Donnelly, et. alDonnelly, et. al
    22. 22. Radiation RiskRadiation Risk fromfrom Diagnostic ImagingDiagnostic Imaging
    23. 23. Ionizing RadiationIonizing Radiation  Radiation capable of producing ionizationRadiation capable of producing ionization in tissues and which can be absorbedin tissues and which can be absorbed  Continuously present in our environmentContinuously present in our environment – background radiationbackground radiation  Average exposure 3 mSv/year in US,Average exposure 3 mSv/year in US, varies widelyvaries widely – Cosmic rays, radon, radiation from rock,Cosmic rays, radon, radiation from rock, natural radionuclidesnatural radionuclides – 4-5 mSv in Denver4-5 mSv in Denver
    24. 24. Ionizing RadiationIonizing Radiation  Used in diagnostic imagingUsed in diagnostic imaging – Radiography, fluoroscopy, angiography,Radiography, fluoroscopy, angiography, nuclear medicine, CT scanningnuclear medicine, CT scanning  Medical radiation is the largestMedical radiation is the largest source of man-made radiationsource of man-made radiation
    25. 25. Radiation fromRadiation from Diagnostic ImagingDiagnostic Imaging
    26. 26. CT Scanning UseCT Scanning Use  From 1991 to 1999 CT scans increasedFrom 1991 to 1999 CT scans increased from 6.1% to 11% of radiologyfrom 6.1% to 11% of radiology procedures in a busy academic centerprocedures in a busy academic center  CT scanning accounted for 67% of theCT scanning accounted for 67% of the effective dose from diagnostic radiologyeffective dose from diagnostic radiology  11% of the patients were less than 1611% of the patients were less than 16 Mettler, J. Radiol. Prot. 20 (2000) 353-359Mettler, J. Radiol. Prot. 20 (2000) 353-359
    27. 27. CT ScanningCT Scanning  2000 – 11% of exams, 67% of dose2000 – 11% of exams, 67% of dose – Mettler, J. Radiol. Prot. 20 (2000) 353-359Mettler, J. Radiol. Prot. 20 (2000) 353-359  2002 – 15% of exams, 75% of dose2002 – 15% of exams, 75% of dose – Weist Semin Ultrasound CT MR. 2002;23:402-10Weist Semin Ultrasound CT MR. 2002;23:402-10
    28. 28. Why Emphasize CT?Why Emphasize CT?  CT provides 75% of the current USCT provides 75% of the current US population radiation exposure frompopulation radiation exposure from diagnostic imagingdiagnostic imaging  CT use continues to growCT use continues to grow  Methods are available to markedlyMethods are available to markedly reduce dosereduce dose
    29. 29. Radiation from Diagnostic ImagingRadiation from Diagnostic Imaging  Upper GI series and VCUG haveUpper GI series and VCUG have radiation doses similar to CTradiation doses similar to CT scanningscanning
    30. 30. One CT can has the sameOne CT can has the same radiation dose as about howradiation dose as about how many chest radiographs?many chest radiographs? 1.1. 0.50.5 2.2. 1010 3.3. 5050 4.4. 100100
    31. 31. Estimated Medical Radiation DosesEstimated Medical Radiation Doses for 5 Year-Old Childfor 5 Year-Old Child Imaging AreaImaging Area Effective DoseEffective Dose (mSV)(mSV) EquivalentEquivalent Number of CXRSNumber of CXRS 3-view ankle3-view ankle .0015.0015 1/14th1/14th 2-view chest2-view chest .02.02 11 Anteroposterior and lateral abdomenAnteroposterior and lateral abdomen .05.05 2.52.5 Tc-99mTc-99m22 radionuclide cystogramradionuclide cystogram .18.18 99 Tc-99m radionuclide bone scanTc-99m radionuclide bone scan 6.26.2 310310 FDG PETFDG PET3 scanscan 15.315.3 765765 Upper GI/small bowel follow throughUpper GI/small bowel follow through 11 5050 Head CTHead CT 44 200200 Chest CTChest CT 33 150150 Abdomen CTAbdomen CT 55 250250 CXR, chest radiograph; Tc99m, technetium 99m; FDG PET, fluorodeoxygluecose positron emission tomography. Data provided by R. Reiman MD. Personal Communication. Duke Office of Radiation Safety. http:// www.safety.duke.edu/RadSafety/
    32. 32. Things We Know About IonizingThings We Know About Ionizing RadiationRadiation  High dose radiation (> 100 mSv) isHigh dose radiation (> 100 mSv) is known to increase the risk of cancerknown to increase the risk of cancer  Children are at higher risk thanChildren are at higher risk than adultsadults
    33. 33. Radiation Risk for ChildrenRadiation Risk for Children  Cancer risk increases with decreasingCancer risk increases with decreasing ageage  The smaller the patient the higherThe smaller the patient the higher the exposure from the samethe exposure from the same techniquetechnique
    34. 34. Risk is Age DependentRisk is Age Dependent Cancer risk forCancer risk for a 4 year old isa 4 year old is likely 3-5 timeslikely 3-5 times greater than forgreater than for a 40 year olda 40 year old _____ ICRP 60_____ ICRP 60 _ _ _ _ BEIR V_ _ _ _ BEIR V
    35. 35. Dose is Size DependentDose is Size Dependent Dose in aDose in a 4 year old4 year old is up tois up to two timestwo times higher thanhigher than in a 40in a 40 year oldyear old
    36. 36. Things We Don’t Know AboutThings We Don’t Know About RadiationRadiation  How low level radiation (below 100How low level radiation (below 100 mSv, especially below 10 mSv)mSv, especially below 10 mSv) affects the risk of canceraffects the risk of cancer
    37. 37. Risk from Low Dose RadiationRisk from Low Dose Radiation  The body of literature on low levelThe body of literature on low level radiation is large and confusingradiation is large and confusing  Data are available to supportData are available to support increased, decreased, or no risk ofincreased, decreased, or no risk of cancercancer  Few of these data are taken fromFew of these data are taken from diagnostic imaging exposurediagnostic imaging exposure  All of the data are open toAll of the data are open to interpretationinterpretation
    38. 38. Consensus StatementsConsensus Statements on Radiation Riskon Radiation Risk
    39. 39. Biological Effects of Ionizing RadiationBiological Effects of Ionizing Radiation Report VIIReport VII US National Academy of ScienceUS National Academy of Science ““A comprehensive review of theA comprehensive review of the available biological and biophysical dataavailable biological and biophysical data supports a “linear no threshold” (LNT)supports a “linear no threshold” (LNT) risk model-that the risk of cancerrisk model-that the risk of cancer proceeds in a linear fashion at lowerproceeds in a linear fashion at lower doses without a threshold and that thedoses without a threshold and that the smallest dose has the potential to causesmallest dose has the potential to cause a small increase in risk to humans”a small increase in risk to humans”
    40. 40. Health Physics SocietyHealth Physics Society ““There is substantial and convincingThere is substantial and convincing scientific evidence for health risksscientific evidence for health risks following high-dose exposures.following high-dose exposures. However, below 50-100 mSv, risksHowever, below 50-100 mSv, risks of health effects are either too smallof health effects are either too small to be observed or are nonexistent”to be observed or are nonexistent”
    41. 41. Health Physics SocietyHealth Physics Society ““The Society has concluded thatThe Society has concluded that estimates of risk should be limited toestimates of risk should be limited to individuals receiving a dose of 50individuals receiving a dose of 50 mSv in one year or a lifetime dose ofmSv in one year or a lifetime dose of 100 mSv in addition to natural100 mSv in addition to natural background.”background.”
    42. 42. The Definitive StudyThe Definitive Study  The background fatal cancer rate isThe background fatal cancer rate is approximately 20%approximately 20%  Assume a 1 in 2000 risk of a fatalAssume a 1 in 2000 risk of a fatal cancer from diagnostic imagingcancer from diagnostic imaging  The study must detect the differenceThe study must detect the difference between 0.2000 and 0.2005between 0.2000 and 0.2005  Millions of subjects would be neededMillions of subjects would be needed Land, Science 1980;209:1197-1203Land, Science 1980;209:1197-1203
    43. 43. The Definitive StudyThe Definitive Study  Other methodologies, such as caseOther methodologies, such as case control studies, require fewercontrol studies, require fewer subjectssubjects  These studies are open to additionalThese studies are open to additional methodological criticismmethodological criticism  A convincing answer is unlikely soonA convincing answer is unlikely soon  It is impossible to prove a negativeIt is impossible to prove a negative Land, Science 1980;209:1197-1203Land, Science 1980;209:1197-1203
    44. 44. I Need a NumberI Need a Number  The most widely used estimate ofThe most widely used estimate of risk of cancer from ionizing radiationrisk of cancer from ionizing radiation is 5% per sievert (Sv).is 5% per sievert (Sv).  Diagnostic imaging doses are in theDiagnostic imaging doses are in the millisievert (mSv) range (5 mSv formillisievert (mSv) range (5 mSv for abdominal CT)abdominal CT)  Risk for 1 CT = 1 in 4,000Risk for 1 CT = 1 in 4,000
    45. 45. What Should We Do?What Should We Do?
    46. 46. Is it reasonable to believe thatIs it reasonable to believe that ionizing radiation from diagnosticionizing radiation from diagnostic imaging can increase cancer?imaging can increase cancer?
    47. 47. Is it reasonable to believe thatIs it reasonable to believe that ionizing radiation from diagnosticionizing radiation from diagnostic imaging can increase cancer?imaging can increase cancer? What is the benefit thatWhat is the benefit that justifies this risk?justifies this risk?
    48. 48. Benefit of CT ScanningBenefit of CT Scanning
    49. 49. CT Alters TreatmentCT Alters Treatment  Children with seizuresChildren with seizures  Adults with strokeAdults with stroke  Blunt abdominal traumaBlunt abdominal trauma  AppendicitisAppendicitis  Spine traumaSpine trauma  Diffuse lung diseaseDiffuse lung disease
    50. 50. Avoiding SurgeryAvoiding Surgery  29,200 children undergoing general29,200 children undergoing general anesthesiaanesthesia  95% normal or mild systemic disease95% normal or mild systemic disease Cohen MM, Anesth Analg 1990;70:160-167Cohen MM, Anesth Analg 1990;70:160-167
    51. 51. Risk of SurgeryRisk of Surgery  29,200 children undergoing general29,200 children undergoing general anesthesiaanesthesia  95% normal or mild systemic disease95% normal or mild systemic disease  1 in 30 risk of a “major event”1 in 30 risk of a “major event” Cohen MM, Anesth Analg 1990;70:160-167Cohen MM, Anesth Analg 1990;70:160-167
    52. 52. Risk of SurgeryRisk of Surgery  29,200 children undergoing general29,200 children undergoing general anesthesiaanesthesia  95% normal or mild systemic disease95% normal or mild systemic disease  1 in 30 risk of a “major event”1 in 30 risk of a “major event”  1 in 2500 risk of death1 in 2500 risk of death Cohen MM, Anesth Analg 1990;70:160-167Cohen MM, Anesth Analg 1990;70:160-167
    53. 53. Risk of HospitalizationRisk of Hospitalization  33,000,000 hospital admissions33,000,000 hospital admissions annually in the United Statesannually in the United States  44,000 to 98,000 deaths from44,000 to 98,000 deaths from medical errorsmedical errors  > 1 in 1000 risk of death from a> 1 in 1000 risk of death from a medical error per hospitalizationmedical error per hospitalization Kohn, National Academy Press 2000Kohn, National Academy Press 2000 http://newton.nap.edu/books/0309068371/html/http://newton.nap.edu/books/0309068371/html/ index.htmlindex.html
    54. 54. If an institution performs 300 CTIf an institution performs 300 CT scans per year, the risk benefitscans per year, the risk benefit equation balances if CT saves oneequation balances if CT saves one life every 4 yearslife every 4 years ““a no brainer”a no brainer” Haaga AJR 2001;177:289-291Haaga AJR 2001;177:289-291
    55. 55. Maximizing theMaximizing the Benefit/Risk RatioBenefit/Risk Ratio
    56. 56. Maximizing the Benefit/Risk RatioMaximizing the Benefit/Risk Ratio  Consider modalities that do not useConsider modalities that do not use ionizing radiationionizing radiation  Optimize imaging protocolsOptimize imaging protocols  Decrease unnecessary examinationsDecrease unnecessary examinations  ALARAALARA  Image qualityImage quality
    57. 57. Is Radiation Necessary?Is Radiation Necessary?  Magnetic resonance imagingMagnetic resonance imaging  UltrasoundUltrasound  Non-imaging evaluationNon-imaging evaluation
    58. 58. Is Radiation Necessary?Is Radiation Necessary?  Magnetic resonance imagingMagnetic resonance imaging  UltrasoundUltrasound  Non-imaging evaluationNon-imaging evaluation  Not doing a CT scan reduces theNot doing a CT scan reduces the radiation by 100%radiation by 100%
    59. 59. Maximizing the Benefit/Risk RatioMaximizing the Benefit/Risk Ratio  ALARA (As low as reasonablyALARA (As low as reasonably achievable) CT techniqueachievable) CT technique  Designing imaging protocols toDesigning imaging protocols to reduce radiation exposurereduce radiation exposure  Reducing unnecessary imagingReducing unnecessary imaging
    60. 60. CT Scanning and DoseCT Scanning and Dose  Changing CT dose primarily affectsChanging CT dose primarily affects images by altering image noiseimages by altering image noise  Higher dose results in decreasedHigher dose results in decreased image noiseimage noise  The larger the patient, the higher theThe larger the patient, the higher the dose needed to produce the samedose needed to produce the same amount of noiseamount of noise
    61. 61. CT #1
    62. 62. CT #2
    63. 63. Which CT Is Noisier? #1 #2
    64. 64. #1 Had Twice the Dose of #2 #1 #2
    65. 65. CT #5
    66. 66. CT #6
    67. 67. Which CT Is Noisier? #5 #6
    68. 68. #5 Had Three Times the Dose of #6 #5 #6
    69. 69. #5 Had Three Times the Dose of #6 21 years old 4 years old
    70. 70. Technique forTechnique for High–ResolutionHigh–Resolution Chest CTChest CT WeightWeight (kg)(kg) mAsmAs kVpkVp SliceSlice IntervalInterval (mm)(mm) 1-7.51-7.5 10-2010-20 100100 55 7.5-107.5-10 20-2520-25 100100 7.57.5 10-12.510-12.5 3030 100100 7.57.5 12.5-1512.5-15 2525 120120 1010 15-2015-20 3030 120120 1010 20-2520-25 3535 120120 1010 25-3525-35 4040 120120 1010 35-5035-50 4545 120120 1010 50-7050-70 5050 120120 1010 AdultAdult 100100 120120 1010
    71. 71. Imaging ProtocolsImaging Protocols
    72. 72. Imaging Protocols that ReduceImaging Protocols that Reduce Radiation ExposureRadiation Exposure  Scan only the area of interestScan only the area of interest  Use techniques that require lessUse techniques that require less radiationradiation
    73. 73. 6 Year Old, Pulmonary Cavity6 Year Old, Pulmonary Cavity  ? Underlying congenital abnormality? Underlying congenital abnormality  CT scan showed no other diseaseCT scan showed no other disease  Chest radiograph showed improvementChest radiograph showed improvement  CT scan requested to re-evaluateCT scan requested to re-evaluate
    74. 74. 6 Year Old, Pulmonary Cavity6 Year Old, Pulmonary Cavity  ? Underlying congenital abnormality? Underlying congenital abnormality  CT scan showed no other diseaseCT scan showed no other disease  Chest radiograph showed improvementChest radiograph showed improvement  CT scan requested to re-evaluateCT scan requested to re-evaluate  Limit CT to upper lobes, avoid thyroidLimit CT to upper lobes, avoid thyroid  Use breast shieldsUse breast shields
    75. 75. Pulmonary Embolism Imaging atPulmonary Embolism Imaging at a Children’s Hospitala Children’s Hospital  Increasing requests for CT pulmonaryIncreasing requests for CT pulmonary angiograms in children prompted a reviewangiograms in children prompted a review of imagingof imaging  Most pediatric chest radiographs areMost pediatric chest radiographs are normal or minimally abnormal, decreasingnormal or minimally abnormal, decreasing the number of indeterminate ventilationthe number of indeterminate ventilation perfusion scansperfusion scans  Additional diagnoses such as heart diseaseAdditional diagnoses such as heart disease and cancer rare in childrenand cancer rare in children
    76. 76. Pulmonary Embolism ImagingPulmonary Embolism Imaging  15% of ventilation perfusion scans15% of ventilation perfusion scans indeterminateindeterminate  10% of CT pulmonary angiograms10% of CT pulmonary angiograms technically limitedtechnically limited  Breast dose with CT 30X greaterBreast dose with CT 30X greater than with ventilation/perfusion scanthan with ventilation/perfusion scan
    77. 77. Pulmonary Embolism ImagingPulmonary Embolism Imaging  15% of ventilation perfusion scans15% of ventilation perfusion scans indeterminateindeterminate  10% of CT pulmonary angiograms10% of CT pulmonary angiograms technically limitedtechnically limited  Breast dose with CT 30X greaterBreast dose with CT 30X greater than with ventilation/perfusion scanthan with ventilation/perfusion scan  Perfusion scanning recommended asPerfusion scanning recommended as first study in patients with normalfirst study in patients with normal CXRsCXRs
    78. 78. Limiting ExaminationsLimiting Examinations
    79. 79. Limiting ExaminationsLimiting Examinations  1/3 of diagnostic examinations in the1/3 of diagnostic examinations in the United States are estimated to beUnited States are estimated to be inappropriate or noncontributoryinappropriate or noncontributory National Imaging Associates web siteNational Imaging Associates web site
    80. 80. 6 Year Old, Pulmonary Cavity6 Year Old, Pulmonary Cavity
    81. 81. 6 Year Old, Pulmonary Cavity6 Year Old, Pulmonary Cavity  CT scan ordered “just to check”CT scan ordered “just to check”  Child doing clinically wellChild doing clinically well  No surgery plannedNo surgery planned
    82. 82. CT Scan Cancelled
    83. 83. Pulmonary EmbolismPulmonary Embolism  Deep vein thrombosis on ultrasoundDeep vein thrombosis on ultrasound – Positive in 11 of 15 patients withPositive in 11 of 15 patients with pulmonary embolismpulmonary embolism  D-dimer levelD-dimer level – Normal in 0 of 10 patients withNormal in 0 of 10 patients with pulmonary embolismpulmonary embolism – Elevated in 9 of 12 patients withoutElevated in 9 of 12 patients without pulmonary embolismpulmonary embolism Victoria, et al. Society for Pediatric RadiologyVictoria, et al. Society for Pediatric Radiology Annual Meeting, Miami, FL USA; 21 April 07Annual Meeting, Miami, FL USA; 21 April 07
    84. 84. CT for Pulmonary EmbolismCT for Pulmonary Embolism  IF D-dimer is negativeIF D-dimer is negative oror ifif ultrasound is positive, no chestultrasound is positive, no chest imaging other than chest radiographimaging other than chest radiograph is neededis needed
    85. 85. GuidelinesGuidelines  Many guidelines are available thatMany guidelines are available that include recommendations forinclude recommendations for imagingimaging  The National Guideline ClearinghouseThe National Guideline Clearinghouse – Worldwide guidelines includedWorldwide guidelines included – Over 2000 guidelinesOver 2000 guidelines – www.guideline.govwww.guideline.gov
    86. 86. Gastroesophageal RefluxGastroesophageal Reflux  Upper GI radiation dose approximatelyUpper GI radiation dose approximately 1.5 mSv1.5 mSv  Recommendations of the North AmericanRecommendations of the North American Society for Pediatric Gastroenterology andSociety for Pediatric Gastroenterology and NutritionNutrition  ““A thorough history and physicalA thorough history and physical examination is generally sufficient to allowexamination is generally sufficient to allow the clinician to establish the diagnosis ofthe clinician to establish the diagnosis of uncomplicated GER (the ‘happy spitter’).”uncomplicated GER (the ‘happy spitter’).”  ““An upper gastrointestinal series is notAn upper gastrointestinal series is not required unless there are signs ofrequired unless there are signs of gastrointestinal obstruction.”gastrointestinal obstruction.”
    87. 87. Image QualityImage Quality
    88. 88. Chest CT RequestChest CT Request  5 yo with chronic cough and failure5 yo with chronic cough and failure to thriveto thrive  On treatment for gastroesophagealOn treatment for gastroesophageal refluxreflux  Fundoplication planned if CT showsFundoplication planned if CT shows bronchiectasisbronchiectasis
    89. 89. 5 Year Old, ? Bronchiectasis
    90. 90. Speaking to PatientsSpeaking to Patients and Familiesand Families
    91. 91. Speaking to Families andSpeaking to Families and PatientsPatients  Participation in medical care shouldParticipation in medical care should include the decision to performinclude the decision to perform diagnostic imagingdiagnostic imaging  15% informed of radiation risk of CT15% informed of radiation risk of CT  9% informed of alternatives to CT9% informed of alternatives to CT scanningscanning Lee CI AJR 2006;187:282-7Lee CI AJR 2006;187:282-7
    92. 92. Explaining Radiation RiskExplaining Radiation Risk  Families are more interested inFamilies are more interested in efforts to control the risk than theefforts to control the risk than the actual numberactual number  After reading a handout on radiationAfter reading a handout on radiation risk, preference for CT over norisk, preference for CT over no imaging decreased, but no familiesimaging decreased, but no families refused CTrefused CT Larson, et al. AJR 2007:189;271-275Larson, et al. AJR 2007:189;271-275
    93. 93. What Do Families Want toWhat Do Families Want to Know?Know?  The examination is needed to bestThe examination is needed to best care for their childcare for their child  The risk of the examination is real,The risk of the examination is real, but very lowbut very low  The examination is being performedThe examination is being performed with the lowest possible riskwith the lowest possible risk
    94. 94. SummarySummary  Ionizing radiation from diagnosticIonizing radiation from diagnostic imaging may cause a very smallimaging may cause a very small increase in the risk of cancerincrease in the risk of cancer  For an indicated CT scan, the likelyFor an indicated CT scan, the likely benefit is far greater than thebenefit is far greater than the estimated riskestimated risk  Pediatricians and radiologists shouldPediatricians and radiologists should work together to make thework together to make the population exposure ALARApopulation exposure ALARA

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