First 303 words of the document:
Magnetic Resonance Imaging
What is it used for?
MRI scans can be used to detect disease throughout the body
In the brain it can be used to look for: bleeding, swelling,
aneurysms, stroke and tumours
How does it work?
Structural Technique Shows structures of the brain
Image looks like a slice of the brain
Uses a powerful magnetic field to influence hydrogen atoms in water molecules
Protons act like compass needles so they all point in the
Radio waves are passed through the head by the scanner
As protons return to their original position, they emit
Different areas of the brain emit different amount of radio
waves and variation occurs with difference in densities
Lots of hydrogen atoms = white
Few hydrogen atoms = dark
What would it be like to have it?
An MRI scanner contains a motorised bed that is moved
around depending on the area being scanned.
You will be able to talk to the operator through a headset because they will be in another
room to you.
Sometimes you are able to have someone with you in the scanning room such as a parent
if you are a young child.
You have to stay very still during the scan and would be asked at intervals to hold you r
breath for a short time.
The scan should take somewhere between 15-90
minutes depending on the size of area being
The machine will be very loud and these are loud
knocking noises coming from the electric current
and you would be given headphones or earplugs
to reduce the noise.