Mini C-Arm Credentialing Course

1. Mini C-Arm CredentialingCourse

2. Course Overview • 1.    Introduction–15 minutes A. Regulatory requirements B. Introduction to HHS Policy Manual “Use of Mini C-arms by a Physician other than a Radiologist” C. Fluoro Policies and Procedures- fluoro time reports, pregnant patients, lead aprons, badges D.  Radiation Badge procedures, contacts E.  PACS implementation and archiving of images

3. Course Overview Cont’d • 2.    Course Content – 120 minutes A.   Fundamental properties of X-rays B.   Discussion of dose and ALARA C.   Biological effects of radiation D.   Image formation- Fluoroscopy, KV, mA, contrast, magnification and digital processing E.   Radiation monitoring F.   Safe practice- distance, shielding of staff and patients, collimation, hand protection, II protection

4. Course Overview Cont’d • 3.    Introduction to the Fluoroscan Mini c-arm - 20 minutes Theoretical Demonstration Hands on training • 4.    Written Examination – 20 minutes   Certification based on passing the test Results forwarded to Chief of Surgery and Chief of Diagnostic Imaging

5. What is a Mini C-Arm? • Fluoroscopy system • X-ray tube fixed relative Image Intensifier by a gantry • Primary beam will not extend past the Image Intensifier • Collimators reduce beam area (field size) to reduce scatter • Shape of the gantry is usually semi-circular “C” • Flexible gantry positioning

6. Introduction:A. Regulatory Requirements • Use of mini c-arm is restricted to extremity imaging and must not be used in other anatomical areas, particularly in children. • The Mini C-Arms at the Hamilton Health Sciences are approved for the following procedures only: Wrist – Ankle – Hand – Elbow – Forearm – Tib/Fib Humerus – Foot – Knee – Femur Any other possible procedure will require permission and supervision from the radiology department.

7. B. HHS Policy Manual • Refer to handout: The Use of Mini C-Arms at HHS by a Physician Other Than A Radiologist • Physicians may become qualified operators of the mini c-arm by successfully completing a course in Radiation Protection and Principles of Fluoroscopy • Once qualified, they may use this device in the operating room and minor surgery procedure room. The operator is responsible for safety and use of mini c-arm. • Standard c-arm requires an M.R.T. to operate • Qualified operator may use only the mini c-arm for fluoroscopy without an M.R.T.

8. C. Fluoro Policies and Procedures 1. Lead Protection The Mini C-Arms at HHS may only be operated when every staff member in the procedure room is correctly attired: • “Lead” protective aprons • approved radiation monitoring badges.

9. 2. Legal Record Patient Information MUST be entered into the patient ID page on the Mini C-arm • Patient Name • Patient Id # • Study description • Physician doing procedure • Accession # will be added by the DI technologist after the case has been logged in to Meditech (required for PACS) • Documentation procedure. Requisitions are to be left on machine in an envelope. DI Techs will pick up, enter in to Meditech and download images to PACS

10. 3. Patient Protection • Patients must be provided with protective lead apparel • For extremity exams this means full apron and thyroid protection • Female patients of childbearing age (11-55) must be asked if there is any chance they may be pregnant • If the answer is no then proceed with the examination • If the answer is anything other than no then you must consult with a radiologist before proceeding with exam- Refer to policy manual Irradiation of Pregnant Patient in Diagnostic Imaging

11. 4. Post Exam Documentation • For female patients of childbearing age “Not Pregnant” or “Pregnant” must be documented on the requisition (Female patients of childbearing age are age 11-55) • Documentation procedure. Requisitions are to be left on the Mini c-arm in an envelope. DI technologists will pick up, enter in to Meditech and download images to PACS

12. 5. Radiation Badges Who Needs to be Badged? • Radiation Workers Definition of a Radiation Worker: • X-ray Safety regulation 861 defines an x-ray worker “ as a worker who as a necessary part of the workers employment may receive a dose equivalent in excess of the limits set out in column 4 of the table”.

13. Safety Code 35 OHSA Dose Schedule

14. D. Radiation Badge Procedures • Badges are changed quarterly • Individuals are responsible to ensure their badge is collected and sent for reading. • Badges are to be kept on-site • 2 badges issued for staff doing or participating in fluoroscopy • One badge is to be worn at waist level under the apron and the second to be worn outside the thyroid collar. (see next slide) • Badge Reports are reviewed by DI staff, photocopied and given to the area to post in a prominent location • For badge issues, contact Jennifer House or Noella Sconci

15. To be worn under the lead apron at waist level

16. To be worn outside the lead thyroid collar

17. July 1, 2006 HHS changed to Global dosimetry • The change standardized vendors across all sites of HHS, St. Joe’s and McMaster University

18. E. PACS • Requisitions are to be left on the Mini c-arm in an envelope • DI technologists will pick up, enter in to Meditech and download images to PACS • Reporting dose is an integral part of patient care • DI technologists must also upload the dose report to PACS

19. COURSE CONTENTA. Properties of X-Rays • X-rays and gamma rays are called IONIZING radiation because they have sufficient energy to dislodge the orbital electrons of an otherwise neutrally charged atom, creating an ion pair. • The electromagnetic spectrum also includes ultraviolet, visible light, Infrared, microwaves and radio waves; they are forms of non-ionizing radiation: radiation that does not have sufficient energy to create ion pairs.

20. Radiation Quiz… Ionizing or Non-Ionizing?

21. Radiation Quiz… Ionizing or Non-Ionizing?

22. Radiation Quiz… Ionizing or Non-Ionizing?

23. Radiation Quiz… Ionizing or Non-Ionizing?

24. Radiation Quiz… Ionizing or Non-Ionizing?

25. Photoelectric and Compton Scattering

26. Electrons… The two kinds of interactions through which the X-rays deposit their energy are both with electrons.

27. 1. Compton interactions

28. Compton Scattering: This has the effect of making the patient’s body a secondary radiation source of scattered X-rays. Scattered radiation in the forward direction may reach the image receptor at a random location and reduce the contrast of the image. Scattered radiation from the patient is also the predominant source of radiation exposure to the radiology personnel.

30. 2. Photoelectric interaction

31. Photoelectric Interactions - Probability of photoelectric interactions occurring is dependent on the atomic number of the material: General relationship: probability of photoelectric interactions αZ3 , where Z is the atomic number. - This is a result of the binding energies moving closer to the X-ray energies in the beam. - Conditions that increase probability of photoelectric interactions: low photon energies and high atomic number materials.

32. Photoelectric Interactions Photoelectric interaction occurs between an X-ray and a tightly bound electron. The X-ray must have enough energy to eject the electron from the atom, and the X-ray is totally absorbed. The probability of photoelectric interactions depends on how well the X-ray energies and the electron binding energies match. The probability of photoelectric interactions is affected by the atomic number of the material because the atomic number changes the binding energies.

33. Approximate Electron Binding Energies (keV)

34. Photoelectric and Compton Scattering The total attenuation coefficient value for materials can vary greatly because of the effect of photoelectric interactions. A minimum value of approximately 0.15 cm2/g is established by Compton interactions.

35. Half-Value Layer The half value layer is simply the thickness of material required to reduce the number of X-rays passing through it to one half of the incident number.

36. Half Value Layer (HVL) Tissue has a HVL of about 4 cm in a typical diagnostic X-ray beam. Therefore a 20 cm thick body would allow only about 3% of the X-rays through it.

37. History • From the very beginning, many had noted the potential problems associated with repeated exposures to high doses of ionizing radiation. • Early X-ray devices were nothing more than glass vacuum tubes. Operators would be repeatedly exposed during the course of a days work. Image copyrighted by Radiology Centennial, Inc.

38. Wives and female assistants often served as test subjects to determine if a tube was “ready” for the day’s work. • Reddening of the skin and burns to the hand were common. Don’t try this at home! Don’t try it at work either! Image copyrighted by Radiology Centennial, Inc.

39. It was not until the death of Clarence Dally (1865-1904), that people agreed: • X-rays could kill as well as cure. • X-rays discovered in 1895 • Radiation survey meters – not till 1928! Dally - Thomas Edison’s assistant in X-ray manufacturing and testing. Image copyrighted by Radiology Centennial, Inc.

40. Anyone remember this? (1920-1960)

41. Radiation Exposure • Obvious injuries such as a burns • More subtle biological effects (cellular level) • The primary cause of cell injury is due to the production of free radicals: OH● molecules generated by the ionization of water. • Free radicals can form other chemical molecules, such as hydrogen peroxide, sodium/potassium hydroxide, and others. • These chemicals can directly damage or destroy a cell’s structure, or cell’s DNA.

42. If the damage is minor, the cell may be able to repair itself. If the damage is severe, the cell may die outright. The effect, or more appropriately, the risk of injury from radiation exposure depends on several factors: The type of radiation (alpha, beta, X, etc.), The energy of that radiation, The intensity and duration of exposure, and, The part of the body being irradiated. Cell Damage

43. Since the discovery of X-rays, it has long been known that very high exposures to radiation over a short period of time will cause very specific effects, from nausea and reddening of the skin, to death. “Deterministic effects are predictable dose related effects and have a threshold below which the effects do not occur, for example radiation induced epilation, erythema and necrosis of skin.” Deterministic Effects

44. Stochastic Effects The other known risk is the potential for cancer due to long term and repeated exposures to high doses of radiation. "Stochastic effects include radiation -induced neoplasm and heritable genetic effects. There is no known threshold for stochastic effects and their severity has no relationship to dose."

45. B. Dose and ALARAUnits To evaluate the potential risk we need to be able to measure and quantify radiation exposure. The units commonly used for this are: 1. The Exposure Unit 2. Radiation Absorbed Dose Unit, and 3. Dose Equivalence Unit.

46. Exposure Unit The exposure unit, known as the Roentgen or “R”, is defined as that quantity of either X or gamma radiation that will, through ionization, produce a total charge of 2.58E-04 coulombs in one kilogram of air at standard temperature and pressure. The SI unit for exposure is the Coulomb per kilogram of air. 1 C/kg = 3876 R

47. Radiation Absorbed Dose The unit of radiation absorbed dose, or “rad”, refers to the amount of energy from ionizing radiation being deposited in matter. The unit can be used for all types of ionizing radiation. 1 rad = 0.01 Joules of energy absorbed per kilogram of material. The SI unit for absorbed dose is the “Gray” or “Gy”. 1 Gy = 100 rad

48. Dose Equivalence • Research has shown that there are different levels of risk of injury, specifically cancer, from exposure to different forms of ionizing radiation: alpha, beta, neutron, X or gamma. Remember, the effect radiation exposure can have on a living cell depends on the type, energy, intensity, duration, and part of the body being exposed. • Concept of dose equivalence provides a common scale for equating the relative risk from exposure to different forms of ionizing radiation.

49. The unit for dose equivalence is the “rem”. It is the product of the absorbed dose in tissue multiplied by a modifying factor. This may also be referred to as a quality factor. For alpha radiation, this quality factor is 20. For beta, X and gamma radiation, this quality factor is 1. The SI unit for dose equivalence is the Sievert (Sv). rem = rad x quality factor 1 Sv = 100 rem Dose Equivalence

50. ALARA The fundamental principle of radiation safety is to keep occupational radiation exposures As Low As is Reasonably Achievable. The three primary ways to apply this principle is through proper application and use of time, distance, and shielding.