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