BL - Radiology

Question 1

What is the difference between deterministic and stochastic effects of radiation?

Answer 1

Deterministic effects only occur once a threshold of exposure has been reached, while stochastic effects follow a linear no-threshold pattern.

Question 2

Give some examples of deterministic effects of radiation

Answer 2

Skin erythema, cataracts, sterility, radiation sickness, nausea

Question 3

Give some examples of stochastic effects of radiation

Answer 3

DNA disruption resulting in cancer or hereditary disorders

Question 4

What are the four ways of measuring radiation? (READ)

Answer 4

• Radioactivity: amount of ionising radiation released by a material
• Exposure: amount of radiation travelling through the air
• Absorbed dose: amount of radiation absorbed by an object/person
• Dose equivalent: combines amount of radiation absorbed and mechanical effects of that type of radiation

Question 5

What units are used to measure radiation?

Answer 5

• absorbed dose is measured in Gray (Gy)

- dose equivalent is measured in Sievert (Sv)

Question 6

True or false - there are no rules in place that state that women must be checked for pregnancy before an X-ray?

Answer 6

False - an enquiry must be made

Question 7

Give some contraindications of MRI scanning

Answer 7

• cardiac pacemaker/implantable defibrillator
• ferromagnetic intracranial aneurysm clip
• implanted/external medication pump
• cochlear implant
• neurostimulation system
• catheter with metallic components