BL Session 13 - Radiology

Question 1

Outline the biological effect of radiation, in deterministic terms.

Answer 1

Effect includes:

• Erythema
• Nausea
• Depilation and cataracts

Question 2

Outline the biological effect of radiation, in stochastic terms.

Answer 2

• Risks include DNA disruption resulting in cancer or hereditary disorders.
• Risk is proportional to dose

Question 3

Outline how one measures radiation.

Answer 3

Measuring radiation:

- R – Radioactivity refers to the amount of ionising radiation released by a material.

- E – Exposure describes the amount of radiation travelling through the air.

- A – Absorbed dose describes the amount of radiation absorbed by an object or person.

- D – Dose equivalent or effective dose combines the amount of radiation absorbed and the medical effects of that type of radiation.

Question 4

How is radiation dose measured?

Answer 4

• Absorbed dose – Gra (Gy)
• Dose equivalent – Sievert (Sv)

Question 5

Sources of ionising radiation.

Answer 5

• Natural – 2.4 mSv

I. Cosmic Rays

II. Plants

III. Our bodies

IV. Radon

V. Radioactive soil and rocks

• Artificial – 0.4 mS v

I. Medicinal

II. Chemicals

Question 6

What are the MRI Contraindications?

Answer 6

• Cardiac pacemaker or implantable defibrillator
• Ferromagnetic intracranial aneurysm clip / FB
• Implanted or external medication pump
• Cochlear implant
• Neurostimulation system
• Catheter that has metallic components

Question 7

Identify the different MRI Planes

Answer 7

• Axial
• Coronal
• Sagittal