Chapter 3 Radiation Safety Vet Tech Institute

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

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

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

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

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

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

Images of Radiation Damage

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

Maximum Permissible Dose (MPD) Maximum dose of radiation that a person may receive in a given period. 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 Sv a year.

A.L.A.R.A. Stands for As Low As Reasonably Achievable 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 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 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

Radiation Exposure Units 2 Categories 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)

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

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

Identify these Monitoring Devices

Practical Application of Radiation Safety Personnel exposure is a result of: 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!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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

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

Secondary (Scatter) Radiation Produced when primary beam interacts with objects in its path. 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. 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. Scatter can be produced in all directions but travels in straight lines.

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

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

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

Get it right the first time!! AVOID RE-TAKES!!!!!!!!!!!!!!!!! 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.

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

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

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

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

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

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