X-Rays (T3)

Question 1

What is the difference between gamma rays and X-rays?

Answer 1

• they differ only in their source of origin

- X-rays are produced by an X-ray generator and gamma radiation is the product of radioactive atoms

Question 2

Describe how traditional X-ray photographs work…

Answer 2

• tend to be absorbed by dense materials more than they are by less dense ones
• for example, bones and teeth absorb most X-rays that are trying to pass through them but soft tissue like muscles, kidneys etc. tend to absorb almost none
• for normal X-ray photographs the beam passes through the relevant part of the patient then hits a film
• the X-rays affect the film in exactly the same way the light does so after it has been developed it will show the bones and teeth up well but is of little or no use for soft tissue

Question 3

What is a CT scan?

Answer 3

• a ‘computed tomography’ scan
• it uses more modern digital technology to detect the X-rays and is much more sensitive than film
• the X-ray source and detector rotate around the patient and then a computer can produce a 3D image

Question 4

Describe radiotherapy…

Answer 4

• the use of very high frequency X-rays to kill cancer cells
• it can carry the risk of causing new cancers but in some cases there is no alternative
• multiple beams often hit the tumour from different directions
• the minimises the potential damage to the surrounding healthy tissue whilst maximising the dose given to the tumour

Question 5

What safety measures are there for staff working with X-rays?

Answer 5

• they stand behind heavy shielding in a different room when an X-ray photograph is being taken
• they are monitored by carrying film badges which are sent away once a month and will show if the wearer has been exposed to any radiation

Question 6

List four uses of X-rays…

Answer 6

• observing the internal
• structure of objects
• airport security scanners
• medical X-rays