BackNext
Section 13: General Information

Operator Qualifications

Purpose

To ensure that all x-ray workers are qualified and trained in the use of radiation.

Standards

Section 5 of the HARP Act states:

  1. "No person shall operate an x-ray machine for the irradiation of a human being unless the person meets the qualifications and requirements prescribed by the regulations.
  2. The following persons shall be deemed to meet the qualifications prescribed by the regulations:
    1. A legally qualified medical practitioner.
    2. A member of the Royal College of Dental Surgeons of Ontario.
    3. A person continuously registered as a chiropodist under the Chiropody Act since before the 1st day of November 1980.
    4. A person registered as a chiropodist under the Chiropody Act after the 1st day of November 1980, who is a graduate of a four-year course of instruction in chiropody.
    5. A person registered as a chiropractor under the Drugless Practitioners Act.
    6. A person registered as an osteopath under the Drugless Practitioners Act.
    7. A radiological technician registered under the Radiological Technicians Act.
    8. A person registered as a dental hygienist by the College of Hygienists of Ontario."

Section 7 of the HARP Act states:

"No person shall cause or permit any other person to operate an x-ray machine for the irradiation of a human being unless the other person meets the qualifications and requirements prescribed by the regulations."

Section 4(3) of the Regulation states:

"Successful completion of one of the following requirements is prescribed for the purposes of sections 5 and 7 of the Act in respect of any person who operates an x-ray machine in a dental diagnostic x-ray facility:
    1. A course in dental radiation safety approved by the Commission.
    2. A program or course in dental assisting that is approved by the Commission at a College of Applied Arts and Technology.
    3. On and after the 1st day of January 1981, a dental assisting program that is approved by the Commission at a Private Vocational School or a Secondary School
    4. A program or course in dental assisting offered by the Canadian Armed Forces.

Procedure

Dental

Dental hygienists must be registered with the College of Dental Hygienists of Ontario. To confirm registration, a copy of the CDHO card for Hygienists should be maintained on file.

Dental assistants must graduate from a course approved by the HARP Commission. A copy of the dental assistant's diploma, a transcript of marks or Ontario Dental Nurses and Assistants Association (ODNAA) card with HARP identified on it should be maintained on file.

Medical

All radiation technologists must be registered with the College of Medical Radiation Technologists of Ontario to work in the Province. Registration must be renewed annually on the technologist's birthday. A system to ensure annual registration by technologists should be implemented.

 

Radiation Safety and Guidelines

Purpose

To ensure that all staff (x-ray workers and clerical) are aware of the polices regarding x-ray safety and to ensure the safe operation of x-ray equipment.

Standards

Section 3(6) of the Regulation states:

"All doors leading directly into an x-ray room shall be fitted with self-closing devices and, where the doors are accessible to the public, shall have prominently displayed on them warning signs sufficient to alert persons to the presence of the x-ray equipment."

Section 8 of the Regulation states:

"(13) Every radiation protection officer shall notify the Director of x-ray Safety forthwith of the occurrence of,

(a) an accident involving an x-ray machine; or

(b) an overexposure to radiation involving a patient or patients, in a facility where he is a radiation protection officer.

(14) In addition to the notice required under subsection (l3), the radiation protection officer shall ensure that a written report of the accident or overexposure is received by the Director of x-ray Safety not later than five days after the occurrence of the accident or overexposure."

Procedure

Issue written instructions to your staff regarding radiation safety practices to be observed in the department. These instructions should include, but not be restricted to, such items as:

  1. who should hold patients;
  2. protective devices to be worn by the person holding the patient;
  3. the requirement that doors be shut during x-ray exposures;
  4. use of restraining devices;
  5. radiation safety policies for pregnant females (staff and patients);
  6. policies for the use of protective devices (staff and patients);
  7. methods for minimizing exposures to patient and operator;
  8. what to do if the x-ray machine breaks down;
  9. what to do if a patient is overexposed. Your facility must develop an internal definition of what constitutes an overexposure;
  10. provide policies to follow when using a mobile radiographic and/or fluoroscopic x-ray machine; and
  11. provide a policy on the use of technique charts must be utilized to ensure consistent film quality;
  12. include 'Action Guidelines' which will be used to identify and correct any problems detected in quality assurance testing -- technical and photographic;
  13. Hospitals only ....a medical directive in place if nurses are permitted to facilitate in ordering x-rays;
  14. policy in place for electronic requisition. Ensure that a Safe-Fail System is in place.

 

Personal Radiation Monitors

Purpose

Personal radiation monitors are worn to ensure x-ray workers do not receive radiation above the prescribed limits.

Standards

Standards for personal monitors may be found in the Regulation respecting X-Ray Safety. - made under the Occupational Health and Safety Act. In addition, maximum permissible exposures may also be found in Health Canada, Safety_ Code 20A.

Equipment

Radiation Monitors - Thermoluminescent Dosimeter (TLD Badges) obtained from the Radiation Protection Bureau (RPB) or from an approved private agency. If using a private agency, ensure they are approved and that records are submitted to the National Dose Registry. For more info on this topic call the RPB at (613) 954-6689.

Procedure
  1. Provide personal radiation monitors to all staff who, as a part of the worker's employment, may be exposed to x-rays and may receive a dose equivalent in excess of the annual limits.
  2. Provide a central location for storing radiation monitors when not in use. This will prevent accidental exposures by other radiation sources.
  3. Ensure all users are aware of their personal radiation badge readings.

 

Protective Devices

Purpose

To provide protection from scattered radiation.

Standards

Section 8(3) of the HARP Regulation states:

"Every radiation protection officer shall ensure that protective accessories of at least 0.5 millimetres lead equivalent at 150 kilovolts peak are available for use by persons who may receive exposure to x-rays in the facility. "

Section 17(1 ) of the HARP Regulation states:

"Every fluoroscopic x-ray machine shall be equipped with,

(g) a shield of at least 0.25 millimetres lead equivalent at 1O0 kilovolts peak that intercepts scattered radiation originating in the patient that would otherwise reach the x-ray operator or other persons in the facility. "

Additional information on protective devices may be obtained from Health Canada, Safety Code 20A and the Ontario Ministry of Labour, Occupational Health and Safety. Act, Ontario Regulation 632/86.

Procedure
  1. Provide lead accessories to those individuals who must remain in the x-ray room with a patient undergoing an examination.
  2. Use protective devices to provide the patient undergoing the examination protection from scattered radiation. Ensure the lead accessory will not interfere with the image.
  3. Ensure the lead protection available meets minimum standards for lead equivalency. Include aprons, scatter curtains, gloves and other protective apparel.

Maximum Kilovoltage

Necessary Lead Equivalent Thickness

Up to 150 kVp

0.5 mm

Up to 125 kVp

0.3 mm

Up to 100 kVp

0.25 mm

Up to 70 kVp

0.15 mm

 

Protective Devices Checks

Purpose

To test protective apparel to ensure there are no cracks or holes that would reduce the shielding capabilities of the protective devices.

Equipment

X-Ray equipment, preferably fluoroscopy machine

Procedure
  1. Visually inspect protective devices on a regular basis to ensure no defects are visible.
  2. Inspect protective devices using radiation at least once every year. This may be done by radiography or fluoroscopy to ensure the devices continue to provide adequate protection.
  3. Maintain a log of the protective devices available in the facility. Record the results of the protective devices checks from the visual checks and the radiation checks. Radiographic films of protective devices do not need to be kept after the results have been recorded.

 

Screens and Cassettes

Condition

Standard

Cassettes and intensifying screens should be inspected at regular interval to maintain them in serviceable condition. On cassettes, hinges and clips are subject to stress and their proper functioning should be checked frequently to ensure that wear has not occurred.

If an intensifying screen is loose in a cassette it should be re-fixed immediately.

Cassettes should be stored open, so that damage to the screens may be avoided. Similarly, cassettes should not be opened in the vicinity of chemicals as there is no way to remove the contamination of chemical splashes from intensifying screens.

The cassettes and screens must be in good condition. Screens that are old and have lost efficiency should be replaced.

Procedure
  1. Observe how cassettes and screens are stored.
  2. Observe whether the cassettes and screen are in good condition.

Routine Cleaning

Standard

Careful inspection and cleaning of intensifying screens at regular interval should be made in order to observe and, if possible, eliminate marks and dirt. The manufacmrer's recommendations concerning cleaning solutions and frequency of cleaning should be followed.

Film/screen Contact

Standard

The felt pad in the back of the cassette may be insecure or worn. This can result in failure of the intensifying screens to maintain uniform contact with the film. This in turn produces a localized area of unsharpness on the radiograph.

Cassettes, at the time of inspection and cleaning, should be tested for film/screen contact. When viewing radiographs, a film which shows an area of localized unsharpness, should initiate an inspection of the cassette from which it came.

Specialized test tools exist to test for film/screen contact.

Light-Tightness of the Film Holder

Standard

Cassettes with broken hinges or clips will not maintain their light-tight integrity. Similarly, cassettes that have been mishandled may also allow light to fog the film. Loose felt pads on intensifying screen may prevent proper closing of the cassettes

 

Technique Charts

Standard

Technique charts should incorporate adjustments for varying thicknesses of body parts. Fixed kilovoltage charts are not recommended as they do not minimize PEEs and they do not optimize image quality (contrast may not be optimum).

There must be a technique chart for each unit in each room. The charts must meet the following design criteria:

  1. Designed according to patient body part thickness, not small medium or large.
  2. Include techniques for pediatric patients by thickness, not age.
  3. Provide the kilovoltage and density selections for automatic exposure control systems.

 

Reject-Repeat Analysis

This program will provide a method for the analysis of the rejected radiographs in a radiology department. The results of such an analysis will provide information concerning those aspects of radiologic imaging that need the most attention.

Equipment
  1. Rejected radiographs and a count of the total number of films consumed during the survey period.

Procedure
  1. Clean out all rejected film bins throughout the department.
  2. Establish a method to accurately determine the amount of raw film consumed starting on the day that the reject film bins were cleaned out.
  3. After a suitable period of time, collect all rejected radiographs and determine the actual number of radiographs exposed during this period.
  4. Analyse all of the rejected films.
  5. Record these numbers on a tally sheet as the films are reviewed.
  6. Determine the overall reject rate.
  7. Determine the percentage of rejects from each of the categories.

Evaluate as follows:

The overall repeat rate must be less than 5 per cent.