key points from radiology new guidance Flashcards
which two organisations are involved in this guidance?
PHE
FGDP
title of guidance
PHE and FGDP 2020 Guidance Notes - Safe Use of Dental X-ray Equipment
who does the guidance apply to?
primarily GDPs
why was the guidance produced?
replaces prev guidance notes from 2001 in response to IRR17 and IRMER17
IRR17
legal duties when using ionising radiation in the workspace
IRMER17
legal duties if exposing pts to ionising radiation
RPA
an individual who is competent to advise on radiation protection
usually a medical physicist (not a dentist)
QA
checks to ensure that your work meets the required standards e.g. ensuring that radiographs are diagnostic and that the dose remains ALARP
controlled area
an area in which a person must take special precautions to restrict significant exposure to ionising radiation
notable changes in the new guidance
image quality rating QA testing of digital display screens contingency plans QA testing of digital receptors dental x-ray room warning signs dose monitoring
why is QA testing of digital receptors necessary?
they are reused (unlike film) and so become damaged over time
how often should QA testing of digital receptors be carried out?
every 3m or whenever damage is suspected
aspects of QA testing of digital receptors
visual inspection
image uniformity
image quality
QA testing of digital receptors - visual inspection fail criteria
damage to wires, casing or phosphor
QA testing of digital receptors - image uniformity
expose receptor to an unattenuated x-ray beam and check resulting image (which should show a consistent shade of grey across entire image area)
QA testing of digital receptors - image uniformity fail criteria
evidence of significant deterioration compared to baseline image
any artefact that may affect clinical image quality
QA testing of digital receptors - image quality
take radiograph of a test object and assess resulting image against a baseline e.g. step wedge
QA testing of digital receptors - image quality fail criteria
evidence of significant deterioration compared to baseline image
image quality rating - A
diagnostically acceptable no/min errors in either pt prep, exposure, positioning, image (receptor) processing or image reconstruction and of sufficient image quality to answer the clinical Q targets - digital ≥95% - film ≥90%
image quality rating - N
diagnostically not acceptable
targets
- digital ≤5%
- film ≤10%
QA testing of digital display screens - why must monitors be routinely checked?
they need the correct properties to accurately display radiographs (such as adequate contrast, resolution, brightness etc)
will deteriorate over time
QA testing of digital display screens
use a suitable test pattern - can access online - SMPTE
should be undertaken every 1-3m
dental x-ray rom warning signs
must be visible at every entrance to a CA
- e.g. doorway of surgery when x-ray equipment is in a
state of readiness to emit x-rays
can be notices/lights and should include the IR trefoil symbol and suitable wording
warning notices need to be removed/covered when the CA is not present (e.g. when power supply to x-ray equipment is turned off)
- coincident warning lights may be more convenient as they can be wired to turn off automatically with the x-ray equipment
contingency plans
immediate actions undertaken in the instance of a “reasonably foreseeable radiation accident”
e.g. pressing the Emergency Stop button if the pan machine fails to rotate but is still exposing the pt to radiation
what must happen if a contingency plan is enacted?
the incident must be investigated (with the RPA) to reduce risk of recurrence
records must be kept for at least 2yrs
HSE must be notified of any significant radiation exposures
how often should staff rehearse contingency plans?
annually
2 types of dose monitoring
monitoring of staff who enter CAs
monitoring of CAs and potential CAs
monitoring of staff who enter controlled areas
RPA can advise when this is necessary
- potentially needed if there are significant changes to
radiographic workload, x-ray equipment, radiographic
techniques or layout of surgery
- can be considered for pregnant employees
personal dose should not exceed 1 millisievert p.a. (otherwise investigation along with the RPA is indicated)