key points from radiology new guidance

Question 1

which two organisations are involved in this guidance?

Answer 1

PHE

FGDP

Question 2

title of guidance

Answer 2

PHE and FGDP 2020 Guidance Notes - Safe Use of Dental X-ray Equipment

Question 3

who does the guidance apply to?

Answer 3

primarily GDPs

Question 4

why was the guidance produced?

Answer 4

replaces prev guidance notes from 2001 in response to IRR17 and IRMER17

Question 5

IRR17

Answer 5

legal duties when using ionising radiation in the workspace

Question 6

IRMER17

Answer 6

legal duties if exposing pts to ionising radiation

Question 7

RPA

Answer 7

an individual who is competent to advise on radiation protection
usually a medical physicist (not a dentist)

Question 8

QA

Answer 8

checks to ensure that your work meets the required standards e.g. ensuring that radiographs are diagnostic and that the dose remains ALARP

Question 9

controlled area

Answer 9

an area in which a person must take special precautions to restrict significant exposure to ionising radiation

Question 10

notable changes in the new guidance

Answer 10

image quality rating
QA testing of digital display screens
contingency plans
QA testing of digital receptors
dental x-ray room warning signs
dose monitoring

Question 11

why is QA testing of digital receptors necessary?

Answer 11

they are reused (unlike film) and so become damaged over time

Question 12

how often should QA testing of digital receptors be carried out?

Answer 12

every 3m or whenever damage is suspected

Question 13

aspects of QA testing of digital receptors

Answer 13

visual inspection
image uniformity
image quality

Question 14

QA testing of digital receptors - visual inspection fail criteria

Answer 14

damage to wires, casing or phosphor

Question 15

QA testing of digital receptors - image uniformity

Answer 15

expose receptor to an unattenuated x-ray beam and check resulting image (which should show a consistent shade of grey across entire image area)

Question 16

QA testing of digital receptors - image uniformity fail criteria

Answer 16

evidence of significant deterioration compared to baseline image
any artefact that may affect clinical image quality

Question 17

QA testing of digital receptors - image quality

Answer 17

take radiograph of a test object and assess resulting image against a baseline e.g. step wedge

Question 18

QA testing of digital receptors - image quality fail criteria

Answer 18

evidence of significant deterioration compared to baseline image

Question 19

image quality rating - A

Answer 19

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%

Question 20

image quality rating - N

Answer 20

diagnostically not acceptable
targets
- digital ≤5%
- film ≤10%

Question 21

QA testing of digital display screens - why must monitors be routinely checked?

Answer 21

they need the correct properties to accurately display radiographs (such as adequate contrast, resolution, brightness etc)
will deteriorate over time

Question 22

QA testing of digital display screens

Answer 22

use a suitable test pattern - can access online - SMPTE

should be undertaken every 1-3m

Question 23

dental x-ray rom warning signs

Answer 23

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

Question 24

contingency plans

Answer 24

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

Question 25

what must happen if a contingency plan is enacted?

Answer 25

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

Question 26

how often should staff rehearse contingency plans?

Answer 26

annually

Question 27

2 types of dose monitoring

Answer 27

monitoring of staff who enter CAs | monitoring of CAs and potential CAs

Question 28

monitoring of staff who enter controlled areas

Answer 28

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)

Question 29

monitoring of CAs and potential CAs

Answer 29

to check if CAs need to remain designated as such, and if adjacent areas need to be designated as CAs should be checked evert 3yrs RPA can advise on best method of monitoring

Question 30

what does IRR17 come under?

Answer 30

H and S at Work Act 1974

Question 31

what is IRR17?

Answer 31

legislative framework for protection of persons who are exposed to IR at work, and other persons e.g. public who may be incidentally exposed

Question 32

components of IRR17

Answer 32

``` 1 - registration with HSE 2 - notify HSE about radon where levels higher 3 - consult a RPA 4 - restriction of exposure to employees and public - optimisation ALARP, dose limits 5 - design of facilities 6 - safety and warning systems 7 - procedural controls 8 - critical examination 9 - radiation risk assessment (with RPA) 10 - controlled areas 11 - dose investigation level <1mSv p.a. 12 - local rules 13 - contingency plans 14 - Radiation protection supervisor 15 - maintenance and examination of engineering controls 16 - information, instruction and training ```

Question 33

dose limits

Answer 33

effective dose 6mSv pa

Question 34

extent of a controlled area

Answer 34

whole room within 1.5m of the xray tube and pt, and within primary beam until it has been sufficiently attenuated by distance or shielding

Question 35

who does IRMER17 apply to?

Answer 35

pts having xrays for diagnostic or tx planning purposes exposure of carers and comforters individuals who have xrays taken using dental x-ray equipment for non-medical reasons pts or other persons who volunteer to take part in research programmes involving xrays

Question 36

GDC CPD radiography recommendation

Answer 36

at least 5hrs of verifiable CPD every 5yr cycle

Question 37

administrative aspects of IRMER17

Answer 37

``` identify staff roles - entitlement of duty holders Employer's procedures Medical physics expert QA of written procedures QA of equipment QA of images ```

Question 38

referrer

Answer 38

HCP entitled to refer individual for xrays | ensure sufficient clinical info provided

Question 39

if referrer is not same person as practitioner what must be provided?

Answer 39

must provide info in writing, include: - pt identification - clinical info (inc any prev medical imaging) - referrer identification - date of referral

Question 40

practitioner

Answer 40

HCP entitled to take responsibility for an individual medical exposure role is justification

Question 41

justification by practitioner

Answer 41

does benefit to pt from diagnostic info obtained outweigh detriment from exposure? - availability and findings of prev radiographs - specific objectives of exposure in relation to history and exam of pt - age (increased radiosensitivity in children) - total potential diagnostic benefit to individual - radiation risk - efficacy, benefits and risk of available alternative techniques having the same objective but involving no/less exposure to IR make a written record of the justification decision 'authorisation' if reject request - record reasons and inform referrer authorisation should be carried out in advance of exposure except e.g. surgery where dentist shouldn't leave to document authorisation. Do ASAP after

Question 42

operator

Answer 42

any person who is trained and entitled, in accordance with EPs, to carry out all or part of the practical aspects associated w a radiographic exam

Question 43

employer

Answer 43

legal responsibility | provide framework, involving written procedures, protocols, QA programmes and training, to ensure safe clinical practice

Question 44

what roles is it common for GDP to be?

Answer 44

referrer, practitioner and operator

Question 45

Employer's Procedures

Answer 45

identify staff roles, training identify individual pregnancy enquiry info on benefits and risks of procedure dose constraints and guidance for carers and comforters clinical evaluation of outcome of each exposure - pt notes assessment of pt dose setting, use and review of DRLs reducing probability and magnitude of accidental/unintended exposures significant and clinically significant accidental or unintended exposures - analysis, recording and reporting - need system in place QA of EPs

Question 46

employer's duties under IRMER

Answer 46

``` produce and ensure EPs are adhered to referral guidelines (inc for dental CBCT if applicable) guideline exposure protocols ```

Question 47

Medical Physics Expert

Answer 47

need to appoint one - person who has knowledge, training and experience to act/give advice on matters relating to physics applied to exposures of the type subject to the regulations - optimisation - measurement methods - using DRLs - advice - liases with RPA where appropriate

Question 48

what must be done for carers and comforters?

Answer 48

carry out risk assessment | every exposure must be justified by practitioner separately to pts exposure

Question 49

exposures taken for non-medical imaging purposes

Answer 49

EPs should detail

Question 50

exposures for research purposes

Answer 50

has to have been approved by a research ethics committee (REC)

Question 51

IRMER17 - 2 major aspects

Answer 51

optimisation of pt dose | administrative aspects

Question 52

IRMER17 - optimisation of pt dose

Answer 52

selection of xray equipment selection of image processing and viewing facilities operation of dental xray equipment use of pt contact shielding (not recommended for routine use)

Question 53

IRMER17 - optimisation of pt dose - selection of x-ray equipment

Answer 53

x-ray source assembly beam filtration (1.5mm Al for ≤70kV) display and recording of parameters relevant to pt dose IO - operating potential 60-70kV - rectangular collimation - FSD at least 200mm - sufficient range of exposure time and/or tube current settings available to enable even the fastest digital imaging systems to be exposed correctly and consistently

Question 54

IRMER17 - optimisation of pt dose - selection of image processing and viewing facilities

Answer 54

display screen equipment and viewing conditions consult MPE film-based imaging systems and viewing conditions - light box

Question 55

IRMER17 - optimisation of pt dose - operation of dental xray equipment

Answer 55

IO - rectangular collimation (40x50mm for size 2 IR) - BAD and IR holders - operating potential (higher setting = lower pt dose = worse image quality) - FSD - select appropriate exposure settings - compatibility with digital IRs IRs - digital dose reduction compared to film - if film - use F speed

Question 56

IRMER17 - optimisation of pt dose - use of pt contact shielding

Answer 56

not recommended for routine use aprons not required ever as main beam should never be directed towards abdomen thyroid shields - better to use appropriate equipment, exposure factors, technique, collimation, field limitation - use if thyroid gland may unavoidably be in primary beam (get advice from MPE)

Question 57

purpose of QA in radiology

Answer 57

ensure consistently adequate diagnostic info, while radiation doses to pts (and other persons) are kept ALARP, taking into account requirements of IRMER17 and IRR17 formal records

Question 58

areas of QA

Answer 58

EPs xray equipment and pt dose image processing and display equipment image quality

Question 59

basic principles of QA

Answer 59

implementation of QA should be responsibility of a named person (usually practice owner or senior partner) only undertaken by suitably trained staff freq defined content of essential supporting records, also freq for formal auditing of the records and required retention times

Question 60

QA programme of EPs

Answer 60

Radiation protection file - radiation risk assessment, local rules, contingency plans and EPs - keep it all together in a known location - maintenance of a procedures log QA procedures for training - register of all staff involved, their responsibilities and training, date for review of training needs

Question 61

QA programme for x-ray equipment

Answer 61

equipment inventory adequate testing routine testing and tests after repairs or modifications in-house QA checks on x-ray equipment

Question 62

QA of clinical image quality

Answer 62

image quality ratings image quality analysis reject image recording and analysis 'N'

Question 63

QA of clinical image quality - image quality analysis

Answer 63

at least every 6m ≥100 images record as well as any actions taken in response

Question 64

QA of clinical image quality - reject image recording and analysis 'N'

Answer 64

record date, nature, known/suspected cause, number of repeats (if taken)

Question 65

QA audits

Answer 65

``` person with overall responsibility for QA programme should check full programme at least every 3years clinical audits/peer reviews - QA programme and associated records - justification and authorisation - CE ```

Question 66

dental x-ray equipment engineers

Answer 66

provide info e.g. room plans | installation of equipment

Question 67

disposal or selling on of x-ray equipment

Answer 67

cut electrical power cable once disconnected from mains, remove/obscure and trefoil symbols - alarm to people tubehead contains lead - get a contractor

Question 68

RPS

Answer 68

person appointed in accordance with IRR17 who is responsible for day to day supervision of work with ionising radiation - e.g. ensures local rules are followed

Question 69

RPA

Answer 69

person consulted in accordance with IRR17, to give advice on radiation protection and compliance with IRR17

Question 70

QA programme for image processing and viewing facilities

Answer 70

QA tests for digital image receptors display screens and viewing conditions film based imaging systems

Question 71

QA programme for image processing and viewing facilities - film based imaging systems

Answer 71

film speed, exp date and recommended storage conditions processing conditions (times and temps) changing freq for processing solutions cleaning instructions for automatic processors QA of film processing - test object e.g. step wedge, after every change of processing solutions QA checks on light-boxes and viewing conditions - at least every 6m

Question 72

QA programme for image processing and viewing facilities - what must you do if manual film processing?

Answer 72

check darkroom/processing unit remains light tight and safelights don't produce fogging of films film for 10mins below safelight with coin on - shouldn't see image of coin on processed film - can do with safelight off to check general light tightness of room - at least every 12m