X-rays

X-rays

Properties
1. Part of the electromagnetic Spectrum
  1. Have short wavelengths
  2. High frequency
  3. High energy
2. Are transverse waves
3. Cause ionisation
  1. add or remove elctrons
4. Affect photographic film
  1. Turn it black
5. Are absorbed by metal and bone
6. Transmitted by healthy body tissue
7. Are useful for medical diagnosis and treatment
Imaging
1. Photographic film
  1. Used in medical imaging
    1. Bone fractures
    2. dental problems
  2. Are transmitted through the body
    1. But are absorbed by bone
  3. White photographic film used in old X-ray machines
    1. Film turns black where x-rays hit it
    2. Stays white where the bones are
2. CCD's
  1. Charged-Coupled Device
  2. Modern X-rays use these
  3. Images are formed electronically
  4. Can be recorded and stored easily
3. CT scans
  1. Gives a 3-D image
    1. Takes multiple images from different angles and puts them together
  2. Computerised tomography
  3. Image can be manipulated to see certain strucutres
  4. Gives doctors lots of insight into problems
Ionising effects
1. Can damage DNA in cells
2. Most damaging to actively dividing cells
3. Cancer treatment
  1. Where cells divide uncontrollably
    1. Due to damaged DNA
    2. Forms tumours
  2. Direct high-energy x-rays at the tumours
    1. Causes lots of damage to cancerous cells
  3. Radiotherapy
4. Low doses cause cancer
5. High doses kill cancer
6. Precautions
  1. Can only have a limited number of X-rays
    1. So they aren't exposed to too much radiation
  2. X-ray machines produce low energy x-rays
    1. Reduces risk of them damaging human tissue
  3. Hospital staff are at an elevated risk
    1. X-ray rooms are sheilded
      1. Have lead built into walls
    2. Have warning signs outside X-ray rooms
  4. Radiographers
    1. Have to routinely leave the room
    2. Stand behind a screen containing lead
    3. Wear lead aprons

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	Created by Elizabeth W over 10 years ago