1.1 X-rays Flashcards
What is an X-Ray?
A high frequency, short wavelength, electromagnetic wave
Describe the wavelength of an X-Ray
About the same size as the diameter of an atom
Name 3 properties of X-Rays
- they affect photographic film in the same way as light
- they are absorbed by metal and bone
- they are transmitted by healthy tissue
Name 2 uses of X-Rays in hospitals
- to make images and ct scans
* to destroy tumours at or near the body surface
Why are X-Rays used to form images?
They are used to form images of bones on photographic film to check for fractures, breaks or dental problems
What are CCDs?
Charged coupled devices, used to form electronic images of X-Rays
What are ct scanners?
Computerised tomography scanners use X-Rays to form images of the cross section of the body, 3D images
What is a contrast medium?
A medium that, when injected and filled into a soft tissue body organ, absorbs X-Rays so they can be seen on a X-Ray image
Why can X-Rays cause damage to living tissue when they pass through it?
X-Rays are ionising, meaning that, because the are the same size as atoms, they can hit the atoms with enough energy that an electron is forced off, causing the DNA in the cells to mutate, keep growing and become cancerous
Name 5 precautions of X-Rays
- limit the number of X-Rays you have
- have low energy X-Rays
- have warning signs outside the room so no one accidentally walks in
- shielded walls made of lead to absorb the X-Rays so there’re less for people to absorb
- have carefully trained radiographers
What is radiotherapy?
The use of direct high energy X-Rays at tumours to cause so much damage to the cancerous cells that they die
What is a high risk of radiotherapy?
As well as killing the cancerous cells, it also kills the normal cells
Name an advantage of a ct scan
Doctors can get a greater insight into people’s injuries as they give 3D images
Which out of X-Rays, CT scans and ultrasounds can…
Distinguish between soft tissue and bone?
All
Which out of X-Rays, CT scans and ultrasounds can…
Distinguish between different types of soft tissue?
X-Ray: not well
CT: pretty well
Ultrasound: very well
