So you get your patient and you slide them into the MRI scanner. The tunnel the person is in is a huge, powerful magnet. You switch on the magnet (please remove all watches and phone prior to this point). The magnet makes the nuclei of hydrogen in water in your body all line up in one direction or the opposite – like iron filings. Then you blast the person with radiowaves and all these nuclei then line up in one direction only. They’re “excited”. Then you switch off the radiowaves, and the nuclei relax, giving off a bit of energy, which you pick up with a detector.
Exactly what that energy is depends on a lot of things to do with the environment the water molecule is in. So you can easily see differences between different types of organs, brain, blood flow and so on. If you know what you’re looking for you can see a huge amount very quickly.
There are lots of different tricks you can play with the machine to look at different things. It’s very powerful. We use the same technology in chemistry to look at atoms in molecules. We don’t look at nuclei in water, but rather look at the nuclei of all the other atoms in our molecule. We can also look at other elements like carbon, nitrogen, fluorine and so on. MRI is usually just H’s in water, since that’s useful in biology.
No, not dangerous at all. There are implants like some older joints and pacemakers that you can’t use with MRI because of the big magnetic field. But generally that’s all it is: magnetic fields and radio waves, both of which we’re bathed in every day. MRI is just a bit more concentrated, but no danger.
It shows you what happens when people ignore the fact that they are in the presence of a giant magnet. Before having an MRI or going near the machine, you need to take off all metal objects which would be attracted to the magnet. Once the magnet is switched on it, anything metal within a couple of metres will be drawn toward the magnet. The closer it is, the stronger the attraction.
The magnetic field is not dangerous to our body, but you wouldn’t want to forget that you had a metal hip implant or a pacemaker!
Aimee and Matt have great answers. The thing to note is that there a few technologies for getting images of our insides. Some have dangers, some have less. MRI is one of the safest. Radio waves are very low-energy electromagnetic radiation that is very very very unlikely to harm us.
Other imaging techniques, like x-rays, computed tomography (CT) scans, use high-energy electromagnetic radiation that is likely to harm us if we get sufficient doses.
So you get your patient and you slide them into the MRI scanner. The tunnel the person is in is a huge, powerful magnet. You switch on the magnet (please remove all watches and phone prior to this point). The magnet makes the nuclei of hydrogen in water in your body all line up in one direction or the opposite – like iron filings. Then you blast the person with radiowaves and all these nuclei then line up in one direction only. They’re “excited”. Then you switch off the radiowaves, and the nuclei relax, giving off a bit of energy, which you pick up with a detector.
Exactly what that energy is depends on a lot of things to do with the environment the water molecule is in. So you can easily see differences between different types of organs, brain, blood flow and so on. If you know what you’re looking for you can see a huge amount very quickly.
There are lots of different tricks you can play with the machine to look at different things. It’s very powerful. We use the same technology in chemistry to look at atoms in molecules. We don’t look at nuclei in water, but rather look at the nuclei of all the other atoms in our molecule. We can also look at other elements like carbon, nitrogen, fluorine and so on. MRI is usually just H’s in water, since that’s useful in biology.
No, not dangerous at all. There are implants like some older joints and pacemakers that you can’t use with MRI because of the big magnetic field. But generally that’s all it is: magnetic fields and radio waves, both of which we’re bathed in every day. MRI is just a bit more concentrated, but no danger.
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Check out this website: http://www.simplyphysics.com/flying_objects.html
It shows you what happens when people ignore the fact that they are in the presence of a giant magnet. Before having an MRI or going near the machine, you need to take off all metal objects which would be attracted to the magnet. Once the magnet is switched on it, anything metal within a couple of metres will be drawn toward the magnet. The closer it is, the stronger the attraction.
The magnetic field is not dangerous to our body, but you wouldn’t want to forget that you had a metal hip implant or a pacemaker!
0
Aimee and Matt have great answers. The thing to note is that there a few technologies for getting images of our insides. Some have dangers, some have less. MRI is one of the safest. Radio waves are very low-energy electromagnetic radiation that is very very very unlikely to harm us.
Other imaging techniques, like x-rays, computed tomography (CT) scans, use high-energy electromagnetic radiation that is likely to harm us if we get sufficient doses.
0