Radiography Flashcards
What is the background radiation dose in the UK?
2.5 mSv
When and by whom were xrays discovered?
Discovered by roentgen in 1895
When was the first x ray taken?
1896
What are the two legislative regualtions surrounding xrays?
IRR (Ionising Radiation Regulations) 1999IRMER (Ionising radiation medical exposure regulations) 2000
Which legislations refers to staff and public safety?
IRR 1999
Which legislations refers to ALARA?
IRMER 2000
What is the IRR 1999?
this relates to the workplace and employeesit is a framework that has been put in place to ensure ionising radiation arising from work activities is kept ALARA and does not exceed specified limits
What the the purpose of IRMER 2000?
aimed at patient protectionminimise the risks to patient undergoing medical exposures
Who enforces IRMER?
CQC (England) and HCI (wales)
what are the four duty holders according to IRMER?
EmployerReferrerpractitioneroperator
What is the role of the referrer?
supply clinical details to allow justification
What must the referrer provide?
sufficient clinical details to enable the practitioner to justify the procedure
What must the referrer to request and xray?
detailed history and exmaination
What is the role of the practitioner?
justify the procedure
How do practitioners justify the procedure?
They need to use selection criteria and previous films to help identify if the risks of radiation outweigh the benefitsrisk benefit analysis
What should be recorded in the patients notes?
Justification
What is the process of recording that justification has taken place called?
authorisation
What is the role of the operator?
they must ensure ALARA principles
What must the operator write in the notes?
record exposure variables if different from the normclinical evaluation of the film must be palced in pt notesDRL should not be exceededQA should ensure films are diagnostic
What is the role of the employer?
need to ensure IRR and IRMER are being implemented
What roles must employers *(legal) people perform?
Notificationrisk assessmentdose limitstrainingQAestablish Diagnostic reference levelsundertake risk assessmentsensure systems are in placeappoint a Radiation protection advisor and supervisorCPD training record
WHen must the health and safety executive be notified?
if a GDP wants to undertake dental radiography he must notify the HSE upon installation of new radiogrpahy equipment and when there has been new owneership of the practice or change of the address
What is the dose limits for classified workers?
20mSv IRR99 /year
What is the dose limit for non-classified workers?
6 mSv IRR 99 /year
What is the dose limit for the general public?
1 mSv IRR 99 / year
What does the dose constraint refer to?
the upper limit of the radiation dose that should not be exceeded
What is the dose constraint for operators ?
1mSv
WHat is the dose constraint for employees not directly involved in radiography?
0.3 mSv
What are diagnostic reference levels? What do the represent? and who set them?
Doses for typical examinations for groups of average sized patients Set by: HPARepresent skin entry dose and should be displaayed next to machineEMPLOYERS MUST TAKE ACTION IF EXCEEDEDMeasures in grays
What is the DRL for a mandibular molar?
2.4mGy
What is the DRL for a DPT?
60mGy
What is the role of the medical physics expert?
provides advice on, 1. patient dose, 2. development and use of new techniques and matters relating to dental exposures
WHat is the role of the radiation protection advisor?
Ensure:1. Safety managment2. Training
T/F all practice must have a RPA?
T IRR99
The medical physics expert adheres to IRR99? T/F
FIRMER 2000
What safety management do RPA’s perform?
- Requirements for controlled areas2. Radiation safety of new equipment and rooms3. Testing and safety devices4. Risk assessment5. INvestigation after radiation incident
What is the role of the RPS?
Ensures local rules are followedIRR99
Who can be appointed a RPS?
anyone in the practice with adequate training
What does IRMER 2000 stipulate about radiographs in the pregnant patient?
Need to ensure that you ask a female of a child bearing age if they are pregnant
WHere should DRL be displayed?
next to xray machine
WHat is excessive exposure of a patient?
when a patient is perceived to have received more than 20 times the intended radiation dose
Who should be contacted in case of excessive exposure?
the RPA and patient must be informed too
if the excessive radaition dose is due to equipment, who should then be contacted?
HSE and MDA
If the excssive radiation dose is due to human error, who should then be contacted?
CQC
What does IRR99 require?
CREWDLLocal rules to be followedRPA and RPSWorking instructionsContingency planDose investigation levelEmployees written procedureRisk assessment
What does IRMER 2000 require?
Roles:Identify referrer, practitioner and operatorMEdical Physics expertPatient:correct identification of patientassessment of pt doseuse DRLCarrying out and recording clinical evaluation of each exposureensure each exposure is authorised so justification can be recorded in pt notesQAclinical auditensure QA programmes are followed
What is radiation hormesis?
concept that at appropriate low doses radiation offers a beneficial effect
WHat are the advantages of low dose radiation?
Deactivates free radicalsstimulated DNA repair mechanismsStimulates immune surveillanceInduces cell death in transformed cells
What are the four ways x rays interact at the atomic level?
Photoelectric effectCompton effectRayleigh scatteringPair production
