How do you limit the dose to patients and yourselves? Flashcards
What do we do when a new patient comes in?
Clinical examintion, then if necessary take a radiograph
Also check if a radiograph has recently been taken.
What is the FGDP?
the FGDP is the Faculty of General Dental Practice (UK)
there are a selection criteria guidelines that help whether a radiograph is needed.
If you decide to take a radiograph what principle do you follow?
ALARP principle (as low as reasonably practicable).
How do you put the ALARP principle into practice?
Equipment - make sure it is working and well maintained and is tested and quality insured, make sure it doesn’t malfunction
Staff training - trained how to use the equipment and use it with good technique reduces doing repeated radiographs.
Reduce exposure factors
How is the dose effected when the kVp is increased?
By increasing the kVp you lower the dose because the x-ray photons have higher energy, more likely to pass through the patient, but we reduce the contrast, so important to find a balance between dose and contrast.
How can we optimise a dose and get a clear image?
By using a digital image, uses a lower dose and it is more sensitive to the x-rays.
The majority of dental practices use digital imaging.
digital imaging has a broader exposure latitude so if you accidentally increase the time or mA it won’t affect the image as much.
How does collimation optimise the dose of the patient?
Collimation is used for intraoral image, the tube matches the shape of the film. So there are no unnecessary areas exposed to x-rays, reducing the dose
How can we optimise the dose when taking an extraoral radiograph?
using field limitation settings.
how else can we reduce the dose?
Protecting the patient by giving them a thyroid shield and lead apron. This protects them from scattered radiation.
not necessary in dental radiography but should be given if the thyroid is in the primary beam.
Controlled area -
“Within the primary x-ray beam until it has been sufficiently attenuated by distance or shielding”
“Within 1.5 m of the x-ray tube and the patient, in any other direction
When is the thyroid in the primary beam and so would need a thyroid shield?
upper occlusal radiography
bisected angle technique
why do we not do dental radiographs on pregnant women?
Because of the emotive nature of radiography during pregnancy, the patient could be given the option of delaying the radiography.”
Risk to the unborn child is negligible. It is safe to take radiographs on pregnant women, however some women maybe apprehensive.
how to reduce radiation exposure for staff?
limit the time
increase the distance - The inverse square law
using shielding - in dental practice may leave the room
what is a classified worker?
If an individual is expected to receive an annual dose which exceeds 3/10 of any annual dose limit then they must be registered as a “classified worker”
Subjected to more thorough dose monitoring and medical surveillance
What is the annual limit of effective does in millisieverts?
20 mSv
what are the two key legislations regarding ionisation?
The Ionising Radiation Regulations 2017 (IRR 17)
The Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER 17)
What are the Ionising Radiation Regulations 2017 (IRR 17)?
Concerned principally with safety of workers and general public
Enforced by Health and safety executives.
what is The Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER 17)?
Concerned with patient safety
Enforced by:
Care Quality Commission in England
Healthcare Inspectorate Wales
Healthcare Improvement Scotland
Regulation and Quality Improvement Authority in Northern Ireland.
How does the IRR effect employers?
Has responsibility to provide a safe working environment for staff and other persons who may enter the premises
What is the radiation protection advisor (RPA)?
An external member to ensure we are compliant with the legislation.
what are the local rules?
local rules are a set of rules for the controlled area which is set by the RPA.
What is the radiation protection supervisor (RPS)?
An RPS must be appointed by the employer to make sure that the local rules are being complied with
An appropriate appointee would be a dentist or dental care professional
They should be closely involved with radiography and received appropriate training
What are the key features of the IRMER legislation?
These regulations protect patients undergoing diagnosis or therapy, medical research studies or medico-legal procedures which involve exposure to ionising radiation
All medical exposures must be justified
The object of this legislation is to restrict the dose to the patient to be as low as possible and still achieve the desired diagnostic or therapeutic result (ALARP)
Dose limits do not apply to patients
What roles does the IRMER involve?
The employer
The referrer
The practitioner
The operator
The medical physics expert (MPE
How does the IRMER effect employers?
Responsible for setting up a framework for the radiation protection of patients
Identification of who is entitled to act as a referrer, practitioner, operator
Ensure that practitioners and operators are adequately trained
Appoint an MPE
Establishment of referral criteria to ensure exposures are justified
Ensure patient doses are optimised (ALARA)
Adopt diagnostic reference levels (DRLs) in consultation with the MPE
