key points from radiology new guidance Flashcards

1
Q

which two organisations are involved in this guidance?

A

PHE

FGDP

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2
Q

title of guidance

A

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

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3
Q

who does the guidance apply to?

A

primarily GDPs

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4
Q

why was the guidance produced?

A

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

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5
Q

IRR17

A

legal duties when using ionising radiation in the workspace

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6
Q

IRMER17

A

legal duties if exposing pts to ionising radiation

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7
Q

RPA

A

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

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8
Q

QA

A

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

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9
Q

controlled area

A

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

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10
Q

notable changes in the new guidance

A
image quality rating
QA testing of digital display screens
contingency plans
QA testing of digital receptors
dental x-ray room warning signs
dose monitoring
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11
Q

why is QA testing of digital receptors necessary?

A

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

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12
Q

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

A

every 3m or whenever damage is suspected

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13
Q

aspects of QA testing of digital receptors

A

visual inspection
image uniformity
image quality

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14
Q

QA testing of digital receptors - visual inspection fail criteria

A

damage to wires, casing or phosphor

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15
Q

QA testing of digital receptors - image uniformity

A

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

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16
Q

QA testing of digital receptors - image uniformity fail criteria

A

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

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17
Q

QA testing of digital receptors - image quality

A

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

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18
Q

QA testing of digital receptors - image quality fail criteria

A

evidence of significant deterioration compared to baseline image

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19
Q

image quality rating - A

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%
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20
Q

image quality rating - N

A

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

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21
Q

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

A

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

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22
Q

QA testing of digital display screens

A

use a suitable test pattern - can access online - SMPTE

should be undertaken every 1-3m

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23
Q

dental x-ray rom warning signs

A

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

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24
Q

contingency plans

A

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

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25
Q

what must happen if a contingency plan is enacted?

A

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

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26
Q

how often should staff rehearse contingency plans?

A

annually

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27
Q

2 types of dose monitoring

A

monitoring of staff who enter CAs

monitoring of CAs and potential CAs

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28
Q

monitoring of staff who enter controlled areas

A

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)

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29
Q

monitoring of CAs and potential CAs

A

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

30
Q

what does IRR17 come under?

A

H and S at Work Act 1974

31
Q

what is IRR17?

A

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

32
Q

components of IRR17

A
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
33
Q

dose limits

A

effective dose 6mSv pa

34
Q

extent of a controlled area

A

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

35
Q

who does IRMER17 apply to?

A

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

36
Q

GDC CPD radiography recommendation

A

at least 5hrs of verifiable CPD every 5yr cycle

37
Q

administrative aspects of IRMER17

A
identify staff roles - entitlement of duty holders
Employer's procedures
Medical physics expert
QA of written procedures
QA of equipment
QA of images
38
Q

referrer

A

HCP entitled to refer individual for xrays

ensure sufficient clinical info provided

39
Q

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

A

must provide info in writing, include:

  • pt identification
  • clinical info (inc any prev medical imaging)
  • referrer identification
  • date of referral
40
Q

practitioner

A

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

41
Q

justification by practitioner

A

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

42
Q

operator

A

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

43
Q

employer

A

legal responsibility

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

44
Q

what roles is it common for GDP to be?

A

referrer, practitioner and operator

45
Q

Employer’s Procedures

A

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

46
Q

employer’s duties under IRMER

A
produce and ensure EPs are adhered to
referral guidelines (inc for dental CBCT if applicable)
guideline exposure protocols
47
Q

Medical Physics Expert

A

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
48
Q

what must be done for carers and comforters?

A

carry out risk assessment

every exposure must be justified by practitioner separately to pts exposure

49
Q

exposures taken for non-medical imaging purposes

A

EPs should detail

50
Q

exposures for research purposes

A

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

51
Q

IRMER17 - 2 major aspects

A

optimisation of pt dose

administrative aspects

52
Q

IRMER17 - optimisation of pt dose

A

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)

53
Q

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

A

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

54
Q

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

A

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

55
Q

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

A

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

56
Q

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

A

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)

57
Q

purpose of QA in radiology

A

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

58
Q

areas of QA

A

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

59
Q

basic principles of QA

A

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

60
Q

QA programme of EPs

A

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

61
Q

QA programme for x-ray equipment

A

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

62
Q

QA of clinical image quality

A

image quality ratings
image quality analysis
reject image recording and analysis ‘N’

63
Q

QA of clinical image quality - image quality analysis

A

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

64
Q

QA of clinical image quality - reject image recording and analysis ‘N’

A

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

65
Q

QA audits

A
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
66
Q

dental x-ray equipment engineers

A

provide info e.g. room plans

installation of equipment

67
Q

disposal or selling on of x-ray equipment

A

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

68
Q

RPS

A

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

69
Q

RPA

A

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

70
Q

QA programme for image processing and viewing facilities

A

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

71
Q

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

A

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

72
Q

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

A

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