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Flashcards in X-rays and ultrasound Deck (8)
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1

What are x-rays?

electromagnetic wave

very short wavelength - same as the diameter of an atom

cause ionisation - adding and removing electrons in atoms

damage cells

2

What are the properties of x-rays that make it useful in medicine?

affect photographic film in the same way as light - turning it black

absorbed by metal and bone

transmitted (pass through) by soft tissue

3

What are CCDs?

charge-coupled device allow images to be formed electronically

allow images to be recorded and stored more easily

4

What are CT scans?

computerised tomography scans involve taking a range of x-ray images from various positions

processed by a computer to build a 3D image

allows the doctors to view different structure and layers in the body

5

What precautions must we take when using x-rays?

x-ray machines are usually low energy to prevent damage

patients are limited to the amount of x-rays they are allowed to have

x-ray rooms have lead walls to protect people outside and staff

6

What are ultrasound waves?

electronic systems produce ultrasound waves that have a higher frequency than what humans can hear (above 20,000Hz)

7

What are the properties of ultrasound waves that make them useful in medicine?

partially reflected when they meet a boundary between two different media

the time taken for the reflection to reach a detector can be used to determine the distance from the boundary

e.g. used in pre-natal scanning and removal of kidney stones

8

How can x-rays be used to treat cancer?

low doses of x-rays may cause cancer, whereas high doses may kill cancerous cells

using high energy x-rays to kill cancerous cells is called radiotherapy