1. Principles of Nuclear Cardiology Thomas H. Hauser MD, MMSc, MPH, FACC Director of Nuclear Cardiology Beth Israel Deaconess Medical Center Assistant Professor of Medicine Harvard Medical School Boston, MA A major teaching hospital of Harvard Medical School

2. Harvard Medical School THH 9/2008 Lecture Schedule 9/8/2008Introduction, Basic PhysicsThomas Hauser, BIDMC 9/15/2008Image ReconstructionTony Parker, BIDMC 9/22/2008Tracers and ProtocolsThomas Hauser, BIDMC 9/29/2008CAD Diagnosis and PrognosisSharmila Dorbala, BWH 10/6/2008Assessment of Myocardial ViabilityMarcelo Di Carli, BWH 10/13/2008Columbus DayNo Lecture 10/20/2008Attenuation ArtifactsThomas Hauser, BIDMC 10/27/2008Technical Aspects of Cardiac CTSuhny Abbara, MGH 11/3/2008Clinical Application of Cardiac CTThomas Hauser, BIDMC 11/10/2008AHANo Lecture 11/17/2008Evaluation of Chest Pain with Cardiac CTUdo Hoffmann, MGH 11/24/2008Coronary Artery PlaqueMel Clouse, BIDMC 12/1/2008RSNANo Lecture 12/8/2008PET/CTMarcelo Di Carli, BWH 12/15/2008"Triple Rule Out" CTVassilios Raptopoulos, BIDMC 12/22/2008Radiation Dosimetry and SafetyThomas Hauser, BIDMC

3. Harvard Medical School THH 9/2008 Advances in Nuclear Cardiology

4. Harvard Medical School THH 9/2008 Advances in Nuclear Cardiology Hachamovich et al, Circulation 2002;105:823-9

5. Harvard Medical School THH 9/2008 Our Goal Image the heart

6. Harvard Medical School THH 9/2008 Our Tools Tracers Camera

7. Harvard Medical School THH 9/2008 Outline Tracers - Nuclear Physics –Atomic structure –Radioactive decay –Specific radionuclides Camera - Gamma Camera –Collimators –Energy selection Radiation Safety

8. Harvard Medical School THH 9/2008 Outline Tracers - Nuclear Physics –Atomic structure –Radioactive decay –Specific radionuclides Camera - Gamma Camera –Collimators –Energy Selection Radiation Safety

9. Harvard Medical School THH 9/2008 Atom

10. Harvard Medical School THH 9/2008 Nucleus Proton –Charge +1 –Mass 1.00728 amu = 938 MeV Neutron –No charge –Mass 1.00866 amu = 939 MeV

11. Harvard Medical School THH 9/2008 E = m 0 c 2 Energy can be converted to mass and vice versa

12. Harvard Medical School THH 9/2008 Notation Element Symbol Atomic Weight {Atomic Number} Oxygen = 16 O = 15 O Carbon = 12 C = 13 C = 11 C

13. Harvard Medical School THH 9/2008 Definitions Nuclide –Specific combination of protons and neutrons ( 12 C) Radionuclide –Nuclide that undergoes radioactive decay ( 11 C) Isotopes –Nuclides that share the same number of protons Same element (identical chemical properties) but different mass

14. Harvard Medical School THH 9/2008 Stable Nuclei

15. Harvard Medical School THH 9/2008 Radioactive Decay Radioactive decay is the process by which unstable nuclei move towards the line of stability by emitting particles and/or photons and releasing nuclear energy

16. Harvard Medical School THH 9/2008 Radioactive Decay Mother nucleus Daughter nucleus Emission Mother Daughter A M  B D + Emission

17. Harvard Medical School THH 9/2008 Modes of Decay α: Emission of a helium nucleus β-: Emission of an electron β+: Emission of a positron γ: Emission of a photon –Isomeric transition –Competes with internal conversion Electron Capture: Absorption of an electron with emission of photons Fission –Formation of two daughter nuclei

18. Harvard Medical School THH 9/2008 What is the difference between a γ-ray and an x-ray? There all just photons!

19. Harvard Medical School THH 9/2008 α Decay

20. Harvard Medical School THH 9/2008 β- Decay

21. Harvard Medical School THH 9/2008 β+ Decay

22. Harvard Medical School THH 9/2008 β+ Annihilation

23. Harvard Medical School THH 9/2008 β+ Annihilation

24. Harvard Medical School THH 9/2008 Electron Capture Releases characteristic x-rays Competes with β+ decay

25. Harvard Medical School THH 9/2008 γ Decay Can occur in conjunction with all other modes of decay Isomeric transition Competes with internal conversion Emission of a conversion electron

26. Harvard Medical School THH 9/2008 What is the emission that we care about as Nuclear Cardiologists? Photons!

27. Harvard Medical School THH 9/2008 Radioactive Decay α β- β + EC

28. Harvard Medical School THH 9/2008 Decay: Half Life

29. Harvard Medical School THH 9/2008 Transient Equilibrium

30. Harvard Medical School THH 9/2008 Technetium Generator

31. Harvard Medical School THH 9/2008 Outline Tracers - Nuclear Physics –Atomic structure –Radioactive decay –Specific radionuclides Camera - Gamma Camera –Collimators –Energy Selection Radiation Safety

32. Harvard Medical School THH 9/2008 Photons Interact with Matter No interaction Photoelectric absorption Compton scattering {Pair production} {Coherent scattering}

33. Harvard Medical School THH 9/2008 Photoelectric Absorption

34. Harvard Medical School THH 9/2008 Compton Scattering

35. Harvard Medical School THH 9/2008 Attenuation

36. Harvard Medical School THH 9/2008 Energy Spectrum 137 Cs

37. Harvard Medical School THH 9/2008 Gamma Camera

38. Harvard Medical School THH 9/2008 Gamma Camera Goals Absorb photons Coming from directly in front of the camera But not the scattered photons

39. Harvard Medical School THH 9/2008 Gamma Camera

40. Harvard Medical School THH 9/2008 Collimator

41. Harvard Medical School THH 9/2008 Why Use a Collimator

42. Harvard Medical School THH 9/2008 NaI(Tl) Crystal

43. Harvard Medical School THH 9/2008 NaI(Tl) Crystal

44. Harvard Medical School THH 9/2008 The Back End Determines position of absorbed photon Accepts only those photons that were not scattered toward the camera

45. Harvard Medical School THH 9/2008 Energy Window: Tc-99m 141keV

46. Harvard Medical School THH 9/2008

47. Harvard Medical School THH 9/2008 Patient Positioning

48. Harvard Medical School THH 9/2008 Raw Data

49. Harvard Medical School THH 9/2008 Outline Tracers - Nuclear Physics –Atomic structure –Radioactive decay –Specific radionuclides Camera - Gamma Camera –Collimators –Energy Selection Radiation Safety

50. Harvard Medical School THH 9/2008 Radiation Safety Time Distance Shielding

51. Harvard Medical School THH 9/2008 Radiation Safety Activity: Becquerel (= 2.7*10 -11 Curie) Absorbed dose: Gray (= 100 rad) Biologically effective dose: Sievert (= 100 rem) Absorbed dose is a function of activity and time Biologically effective dose is the absorbed dose multiplied by a quality factor (for photons, =1)

52. Harvard Medical School THH 9/2008 Example Radiation Exposures

53. Harvard Medical School THH 9/2008 You Exposure Increases by 1 mREM from… Three days of living in Atlanta Two days of living in Denver About seven hours in some spots in the Espirito Santo State of Brazil. An average year of TV watching A year of wearing a luminous dial watch A coast-to-coast airline flight

54. Harvard Medical School THH 9/2008 Time Spend as little time as possible near radiation –Delivered dose is a function of time

55. Harvard Medical School THH 9/2008 Distance The dose of radiation decreases as the square of the distance between you and the source –Increases as the square of the distance as you get closer

56. Harvard Medical School THH 9/2008 Shielding If you must spend a significant amount of time near a radiation source, use as much shielding as possible –Lead –Plastic

57. Harvard Medical School THH 9/2008 Lead Shielding

58. Harvard Medical School THH 9/2008 Plastic Shielding Best for β emitters –Prevents bremsstrahlung

59. Harvard Medical School THH 9/2008 Summary Tracers - Nuclear Physics –Atomic structure –Radioactive decay –Specific radionuclides Camera - Gamma Camera –Collimators –Energy Selection Radiation Safety