Revision Flashcards
Who discovered x-rays?
Wilhelm Conrad Roentgen
when were x-rays discovered?
1895
When were x-rays used for dental?
1896
Why do we have to worry about x-rays?
Can cause ionisation of atoms/molecules in soft tissues
cathode connection
filament
electron beam
tungsten target
glass housing
anode connection
bremsstrahlung and characteristic x-rays
x-rays
filament focusing cup
filament connections
what is the cathode in an x-ray machine made of?
thin wire of tungsten
what is the anode in an x-ray machine made of?
tungsten target embedded in copper
What law gives us the safe distance from a source of x-rays?
Inverse square
law intensity = 1/d2
Name the two ways x-rays are produced in dental radiography:
Characteristic
Bremstrahlung
what is photoelectric effect?
interaction of x-rays with matter
emission of electrons from a material caused by light (electromagnetic radiation)
what is compton scatter?
interaction of x-rays with matter
low energy photons pass through a tissue and collide with molecules producing a change in direction and loss of energy
What does IRMER stand for?
Ionising radiation medical exposure regulations
What does IRR stand for?
Ionising radiation regulations
What are the main differences between IRMER 17 and IRR 17
IRR protects eqipment, staff and general public where as IRMER protects patients
IRR requires RPS (radiation protection supervisor) and RPA (advisor) where as IRMER requires MPE (medical physics expert)
Who in the dental office are effected by IRR and IRMER?
IRR - staff
IRMER - patients
Name the 4 designated roles under IRMER
Employer - legal person
Referrer - doctor/dentist
Practitioner - justifies exposure - dentist
Operator - any person involved in taking the x-ray
Which IRMER role relates to you?
Dentist has entitlement as referrer, practitioner and operator (they can be employer too)
What are Local Rules?
Written rules pertaining to controlled areas
Minimum content:
- Identified designated area
- Name of RPS
- Arrangement for restricting access
- Dose investigation level
- Summary of working instructions
- Contingency arrangement
RPA what does it stand for? what do they do?
Radiation protection advisor
Advises on compliance