Section 3: Quality Assurance
Regulatory Requirements
Acceptance Testing
The following sections of the Healing Arts Radiation Protection Act and its regulation specify the requirements for acceptance testing:
- New X-ray Equipment
Section 8 (4) of the HARP Regulation states:
"Every radiation protection officer shall provide to the director of x-ray safety, within sixty days of the installation of a new x-ray machine in a facility where he or she is the radiation protection officer, written results of the tests conducted to verifywhether or not the x-ray machine complies with the provisions of the Radiation Emitting Devices Act (Canada) and the regulations made thereunder."
- Used X-ray Equipment
Section 8 (5) of the HARP Regulation states:
"Every radiation protection officer shall provide to the Director of X-ray Safety, within sixty days of the installation of a used x-ray machine in a facility where he or she is the radiation protection officer, written results of the tests conducted to verify whether or not the x-ray machine complies with the provisions of the Act and this Regulation."
Routine Quality Control Testing
- Dental Facilities
Section 8 (8) of the HARP Regulation states:
"Every dental radiation protection officer shall ensure that at the facility where the officer acts, the procedures and tests set out in Column 1 of Table 3 are conducted at the frequencies set out opposite thereto in Column 2 of Table 3."
- Chiropody Facilities
Section 8 (9) of the HARP Regulation states:
"Every chiropodic radiation protection officer shall ensure that at the facility where the officer acts, the procedures and tests set out in Column 1 of Table 4 are conducted at the frequencies set out opposite thereto in Column 2 of Table 4."
- Medical and Chiropractic Facilities
Section 8 (10) of the HARP Regulation states:
"Every medical radiation protection officer and every chiropractic radiation protection officer shall ensure that at the facility where the officer acts, the procedures and tests set out in Column 1 of Table 5 are conducted at the frequencies set out opposite thereto in Column 2 of Table 5."
In addition to stipulating mandatory
testing requirements, the HARP Regulation also stipulates maximum exposure limits (Patient Entrance Exposures) to which patients may be exposed for a variety of x-ray examinations.
Medical Patient Entrance Exposure Limits
Section 8 (11 ) of the HARP Regulation states:
"Every medical radiation protection officer, every chiropractic radiation protection officer and every chiropodic radiation protection officer shall ensure that at the facility where the officer acts, the entrance exposure of that part of a patient set out in Column 1 of Table 6 of a thickness set out opposite thereto in Column 2 of Table 6 that is a distance form the x-ray source set out opposite thereto in Column 3 of Table 6 does not exceed the exposure set out opposite thereto in Column 4 of Table 6."
Dental Patient Entrance Exposure Limits
Section 8 (12) of the HARP Regulation states:
"Every dental radiation protection officer shall ensure that at the facility where the officer acts, the entrance exposure of that part of a patient set out in Column ! of Table 7 at the measured potential set out opposite thereto in Column 2 of Table 7 does not exceed the exposure set out opposite thereto in Column 3 of Table 7."
Documentation, Recording and Correction
Measurements
Measurements obtained by the quality assurance technologist or service representative should be clearly documented and be readily available for evaluation and kept on site for six years.
Evaluation of Charted Data and Measurements
It is obviously not enough simply to record the measurements and plot them. The results must be evaluated immediately upon recording the data, compared to previous and/or baseline results and corrective action taken if indicated.
Setting Standards for Variation Allowed
Many tolerance limits are specified in the Healing Arts Radiation Protection Act and its regulation. If these limits are reached or exceeded, corrective action is required. However, for tests which are not covered by the regulation, control limits and operating levels should be established with several points in mind:
- Limits should be set to indicate problems before diagnostically significant changes are evident in the clinical image, but not so restrictive as to require frequent corrective action unless real problems exist;
- Control limits should not be so restrictive that they exceed the capability of the equipment;
- Control limits and operating levels may be adjusted based on experience and may be set closer to the operating level for equipmert used over a limited range or for limited applications.
- Manufacturers' recommendations.
Testing Frequency and Mode of Recording
Each x-ray machine should have a separate and distinct logbook which contains the records of quality control testing results. The frequency of testing is prescribed in the Regulation as stated earlier.
Section 8 (6) of the HARP Regulation states:
"Every radiation protection officer shall ensure that records are maintained of each test required to be carried out under this section that set out,
- the type and result of the test,
- the frequency of testing where applicable; and
- the action taken to correct each deficiency identified by the test."
Section 8 (7) of the HARP Regulation states:
"Every radiation protection officer shall ensure that the records referred to in subsection (6) are maintained for at least six years from the time of their making in the facility in which the x-ray machine to which the records referred is operated"
Methods of Interpretation, Feedback and Correction
Formal means should be established for interpreting the recorded data. There should be a standard procedure for reporting significant problems to service personnel. When a piece of equipment has been repaired, it must be retested to assure that the problem has been corrected. This retest must be documented.
Recording Equipment Downtime and Failure
There is an advantage of having a log book for each x-ray machine, listing the problems that have occurred with it. This is particularly useful for identifying transient problems that may not be serious, and yet, when a pattern develops, indicate the need for correction. This record gives a clearer picture of the percentage of time the machine is not functioning or is malfunctioning and why. The record should also include the length of time required for a vendor or service personnel to respond to the call and repair the equipment. A note should also be made of the time required to obtain spare parts after the service representative was called. This record should be reviewed when decisions are made to purchase additional or replacement equipment. The record can be a valuable measure of the cost effectiveness of the equipment and the vendor's service.
