Chapter 3 Radiation Safety

1. Chapter 3 Radiation Safety Vet Tech Institute

2. Radiation should be respected not Feared! • Safety is Always important! • Stray Radiation Exposure is common, but can be limited. • All radiation equipment must meet state regulations (Department of Health).

3. Safe Operating Procedures Should Include: • An adequate technique chart or comparable system • Positioning aids • Protective clothing and other Protective Barriers • Personnel dosimetry devices • Emergency Procedures for malfunctioning x-ray equipment • Quality control measurements and Tests.

4. Hazards of Ionizing Radiation • All living cells are susceptible to ionizing radiation damage. • Affected cells may be damaged or killed. • Rapidly dividing cells are most sensitive to radiation.

5. 2 types of Biologic Damage can Occur from over-exposure to Radiation • 1. Somatic Damage • 2. Genetic Damage

6. Somatic Damage • Damage to the body that becomes manifest within the lifetime of the recipient. • Skin issues • Cancer • Cataracts • Etc.

7. Genetic Damage • Occurs when the genes of reproductive cells. • Damages DNA. • Can result in gene mutation. • Not detectable until future generations. • May be lethal or only a visible anomaly. • May be latent for generations.

8. Images of Radiation Damage

11. Death by x-ray? • Mortality/Death is caused by exposure to extremely high levels of radiation. • Death has occurred with single dose to 300 rads. • Should never occur to a vet tech!!!! • Technically, no amount of radiation is non-damaging. Even under best conditions, some exposure will occur.

13. Maximum Permissible Dose (MPD) • Maximum dose of radiation that a person may receive in a given period. • No one under 18 is allowed to enter radiographic suite unless ordered by a medical doctor. • Occupationally exposed can receive up to 0.05 Sv (Sieverts) per year. • Non-occupationally exposed can receive up to 0.005 Sv a year.

14. A.L.A.R.A. • Stands for As Low As Reasonably Achievable • Principle based on the knowledge that there is no threshold dose for radiation injury, that is all radiation exposure entails some degree of risk • All individuals working around radiation must consider this concept and act on it by observing all safety procedures and cautions, thus exposing themselves to the least amount of radiation possible

15. Radiation Exposure Units • 2 Categories • 1. Absorbed Dose • The quantity of energy imparted by ionizing radiation to matter per unit mass of the matter. Unit is the gray (Gy). • 1 Gy= 100 rad (The amount of radiation energy absorbed by tissue) • 2. Dose Equivalent • Quantity obtained by multiplying the absorbed dose in tissue by the quality factor. Unit is the Sievert (Sv). • 1 Sv=100 rems (Measure of the amount of radiation that one receives)

17. Patient Exposure • Animal patients are just as susceptible to irradiation damage as humans. • Shielding of the gonads of breeding animals is recommended. • Unnecessary and excessive radiography should always be avoided for any patient in general.

19. Personnel Monitoring Devices • Dosimetry-various methods used to measure radiation exposure to personnel. • Types: • Film Badge • Pocket Ionization Chamber • Thermoluminescent dosimeter (TLD) • Dosimeters- personal exposure monitoring devices

20. Identify these Monitoring Devices

21. Practical Application of Radiation Safety • Personnel exposure is a result of: • 1. Exposure to the primary beam • 2. Exposure from secondary (scatter) radiation • 3. Exposure from “leakage” radiation from the x-ray tube housing IT IS THE RESPONSIBILITY OF THE INDIVIDUAL TO ENSURE HIS OR HER OWN RADIATION PROTECTION AT THE TIME OF EXPOSURE!!!!!!!!!!!!!!!!!!!!!!!!!!!!

22. Collimation, Collimation, Collimation • Collimator limits the primary beam so that scatter or secondary radiation is reduced to the patient and to those assisting with the radiographic procedure.

23. Filters • States require filtration of primary beam. • Composed of 2.5 mm aluminum • Filter is located between the window of x-ray tube and the collimator. • Eliminates less penetrating or “soft” x-rays.

24. Secondary (Scatter) Radiation • Produced when primary beam interacts with objects in its path. • Amount and direction depends on the intensity of the beam, the composition of the structure being radiographed, the kVp level, and the thickness of the patient. • Scatter can be produced in all directions but travels in straight lines.

25. How to limit exposure • Personnel should be as far away from primary beam as possible. • If proper precautions are taken, then no one should receive a significant amount of radiation. • Chemical restraint. • Mechanical restraint.

26. Personal Protective Equipment (PPE) • Lead aprons • Lead gloves • Thyroid Shields • Eye protection • Should have 0.5 mm lead equivalent in aprons, gloves and shields.

28. I see an Artifact • Artifacts- anything on radiograph that should not be there. • Motion artifacts • Cassette artifacts • FINGERS!!

31. Get it right the first time!! • AVOID RE-TAKES!!!!!!!!!!!!!!!!! • Way to do this is to use technique charts and measuring devices. • Refer to pre-existing radiographs and radiograph logs. • This is cost effective and could save time, thus saving a life! • National repeat rate for radiographs is 8 %. Each repeat is another radiation dose to patient and technician.

32. Maintenance of Protective Apparel • Proper care is essential to continued radiation safety. • Veterinary Radiography requires 0.5 mm of lead equivalent because restrainer is close to primary beam. • Aprons should be hung vertically or laid flat when not in use. • Gloves should be placed on vertical holders.

33. Visual inspection should be performed every time apparel is worn. • Any tears or obvious problems should be investigated farther. • If defective, should be replaced or discarded.

34. Radiation Safety Rules • Remove all unnecessary personnel from radiographic suite during exposure. • No one under 18 allowed. • No pregnant women allowed. • Rotate personnel. • Use mechanical restraints when possible. • Use chemical restraint when possible. • Always wear PPE. • Properly care for PPE.

35. Never permit body to be within primary beam. • Use collimation when possible. • Use filters. • Do not aim primary beam at personnel or adjacent rooms. • Never hand hold the x-ray tube. • Wear badges.

36. Avoid re-takes. • Maintain chemicals. • Have machine services and calibrated regularly. • Keep exposure log. • Adhere to safety codes of the state. • Have Patience.

37. http://www.youtube.com/watch?v=3u_8frR0IpE http://www.youtube.com/watch?v=rvAJ_u3Q0Hw&feature=related