What are purposes and scope of inspecting general X-ray equipment for medical use in Vietnam?
What are purposes and scope of inspecting general X-ray equipment for medical use in Vietnam? What is process of inspecting general X-ray equipment for medical use in Vietnam?
I have questions about the above issues, hope to be answered according to the provisions of the law.
What are purposes and scope of inspecting general X-ray equipment for medical use in Vietnam?
In Section I, Appendix III.6 issued together with Circular 08/2022/TT-BKHCN (effective from July 22, 2022) has purposes and scope of inspection of general X-ray equipment for medical use as follows:
1. Purpose
This procedure specifies the verification of composite X-ray equipment for medical use.
2. Scope and subjects of application
This procedure applies to organizations and individuals participating in the inspection of general X-ray equipment for medical use; state management agencies and other relevant organizations and individuals.
What is process of inspecting general X-ray equipment for medical use in Vietnam?
According to Section I.3, Appendix III.6 issued together with Circular 08/2022/TT-BKHCN (effective from July 22, 2022), the inspection of general X-ray equipment for medical use has the following contents: process as follows:
3.1. diagram
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1. Prepare equipment, tools and supplies |
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2.1. Visual inspection |
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3. Inspection result report |
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2.2. Check the peak voltage |
4. Inspection certificate |
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2.3. Check beam timing accuracy |
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2.4. Check exit dose |
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2.5. Check the effective focal size of the X-ray tube |
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2.6. Check the collimation of the X-ray beam |
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2.7. Check the coincidence between bright field and radiation field
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2.8. Primary beam filter test
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3.2. Explain
Step 1: Prepare equipment, tools and supplies.
Step 2.1: Check the appearance
- Check X-ray equipment information.
- Check the mode switch and instructions.
- Check the mechanical operation of the systems.
- Check distance indicator accuracy.
Step 2.2: Check the kVp . peak voltage
- Check peak voltage accuracy
+ Place the multifunction meter or peak voltage measuring device at the center of the platen, 75 cm from the focal point of the emitter or at the distance recommended by the meter manufacturer.
Align the center ray of the X-ray beam to the center of the sensitive part of the measuring device.
+ Focus the beam so that the radiation field covers the entire surface of the radiation sensitive part of the measuring device.
+ Choose to set the parameters of the emitter current (mA) and emission time (ms) or the emission constant (mAs) as appropriate. Change the kVp parameter set on the control cabinet from 50 kVp and gradually increase it by 20 kVp to the highest value of kVp normally used, keeping the set value of the emitter current and beam emission time or of the emission constant. ray.
- Check repeatability of peak voltage
+ Same as above.
+ Choose to set voltage parameters on the control cabinet corresponding to the commonly used voltage value. Perform 3 irradiations with the same applied voltage value and keep the same set values of emitter current, irradiation time or irradiation constant.
Step 2.3: Check beam timing accuracy
- Steps to check the accuracy of beam time
+ Place the beam timing device at the center of the table, 75 cm from the focal point of the emitter or according to the distance recommended by the measuring device manufacturer.
Align the center ray of the X-ray beam to the center of the sensitive part of the measuring device.
+ Focus the beam so that the radiation field covers the entire surface of the radiation sensitive part of the measuring device.
+ Perform irradiation with appropriate voltage setting (usually choose 80 kVp or the closest value to this value) and variable emission time setting values. The measuring device must be cleared (reset to zero) after each measurement.
Step 2.4: Check exit dose
- Check output dose repeatability
+ Place the multifunction meter or dosimeter at the center of the table, 100 cm from the focal point of the emitter, or at a distance close to this value.
Align the center ray of the X-ray beam to the center of the sensitive part of the measuring device.
+ Focus the beam so that the radiation field covers the entire surface of the radiation sensitive part of the measuring device.
+ Perform from 5 x-rays with the same parameter setting voltage and emission time, emitter current or emission constant commonly used in practice for X-ray equipment. The measuring device must be cleared (reset to zero) after each measurement.
- Check output dose linearity
+ Place the multifunction meter or dosimeter at the center of the table, 100 cm from the focal point of the emitter or a distance close to this value.
Align the center ray of the X-ray beam to the center of the sensitive part of the measuring device.
+ Focus the beam so that the radiation field covers the entire surface of the radiation sensitive part of the measuring device.
+ Perform 3 irradiations with the same set voltage of 80 kVp or the closest value to this value and each time with a different set of emission constant mAs most commonly used in practice for X-ray equipment. The measuring device must be cleared (reset to zero) after each measurement.
Step 2.5: Check the effective focal size of the X-ray tube
- Steps to check the focal size
+ Fix the image recorder on a fixed plane.
+ Place the focal size checker directly on the face of the imager according to the inspection tool manufacturer's instructions.
Select the distance from the focus to the imager (SID) according to the test instrument manufacturer's instructions.
+ Perform irradiation with peak voltage setting and irradiance constant according to the test tool manufacturer's instructions (usually 80 kV and 10 mAs).
Step 2.6: Check the collimation of the X-ray beam
- Steps to check beam collimation
+ Position the patient table in a horizontal position, use a balance checker to check the balance of the patient table.
+ Place the image recorder at the center of the table; Adjust the play ball in a direction perpendicular to the tabletop and 100 cm away from the image plate. Where this distance cannot be established, adjust at an appropriate distance.
+ Place the collimator t on the face of the light-field and radiation-field-conformity-checker so that the lower ball of the collimation-checker coincides with the center of the conformance-checker between the light field and the radiation field.
+ Adjust the center of the light field of the beam condenser to coincide with the center of the test tool.
+ Emit rays with parameters kVp and mAs suitable for the speed of the image plate.
Step 2.7: Check the coincidence between the bright field and the radiation field
- Steps to check the light-field and radiation-field coincidence
+ Position the patient table horizontally, use a balance checker to check the balance of the patient table;
+ Place the photo-recording plate at the center of the table; Adjust the ball in a direction perpendicular to the tabletop and 100 cm from the platen or to the distance recommended by the test instrument manufacturer.
+ Place the light-field-radiation-field coincidence test on the surface of the image-recording plate.
Rotate the test device so that the small dot at the lower left corner corresponds to the position of the patient's right shoulder in supine position to allow subsequent determination of the direction of deviation.
+ Adjust the beam concentrator so that the light field covers the test instrument's marked position and the bright field center coincides with the test instrument's center.
+ Beam with parameters kVp and mAs as recommended by the manufacturer of the test instrument.
Step 2.8: Check primary beam filter
- Steps to measure HVL using a multifunction or dosimeter and standard aluminum filters
+ Place the multifunction meter or dosimeter on the table.
+ Adjust the distance from the device to the beam at 75 cm and adjust the radiation field to cover the sensitive area of the measuring device.
+ Beam with the parameters of voltage set 80 kVp and emission constant 50 mAs. Record the radiation dose value recorded on the dosimeter.
+ Reset the dosimeter to zero and add a 0.5 mm thick aluminum plate between the beam concentrator and the dosimeter; perform irradiation and record the reading.
+ Reset the dosimeter mode to 0, repeat these steps with the addition of 0.5 mm or 1 mm aluminum plates in increments until the radiation dose value is about 1/3 of the measured dose value. OK without the aluminum filter.
+ Repeat the above steps for other commonly used kVp voltage values.
Step 3: Report the inspection results
- The inspection results must be made into an inspection record with all the contents according to Form 1. The inspection record is issued together with QCVN 11:2015/BKHCN.
- The inspection minutes must be approved and signed and stamped (if any) by the members:
+ The representative of the establishment using the X-ray equipment or the person authorized by the establishment.
+ The person assigned by the establishment using the X-ray equipment to participate and witness the inspection.
+ The person performing the test.
- Based on the data of the test results in the inspection report, the person performing the verification must calculate and evaluate the working characteristics of the X-ray equipment according to the instructions and make a report on audit assessment according to Form 2. Report on inspection results issued together with QCVN 11:2015/BKHCN.
Step 4: Certificate of inspection
- The certificate of inspection is only issued to the X-ray equipment after it has been tested and concluded to meet the acceptance requirements.
- When the inspected X-ray equipment meets the acceptance requirements, the inspection organization must issue an inspection certificate within 15 working days from the date of approval of the inspection report at the establishment according to the Form 3. Certificate of inspection issued together with QCVN 11:2015/BKHCN.
Best Regards!
