What is an MRI? How does it take the pictures of our brain? What materials are used for it?

1 Answer
Dec 12, 2017

MRI stands for Magnetic Resonance Imaging. A strong magnet, such as Neodymium is used to make a strong field.

Explanation:

MRI stands for Magnetic Resonance Imaging.

A MRI takes a picture of our brain by using a strong magnetic field to align the hydrogen cations(+) in the water molecules in our body. The magnetic alignments are aligned in a strong magnetic field. Then, a radio wave is applied to spin those hydrogen cations. Different tissues have different speeds undergoing those changes, and those changes create a magnetic flux, creating a difference of electrical strength in the receiving coil. By changing where the magnetic field is applied, different pictures can be taken.

For the materials used to create a strong magnetic field, an electromagnet or a permanent magnet can be used. To create a strong magnet, materials such as neodymium can be used. Or, a tightly woven solenoid can be used as a magnet.

Just to mark, a normal MRI has a magnetic field about 1.5 T(Teslas; Units of magnetic field strength). Earth has a magnetic field strength of 0.0000025 T to 0.0000065 T (25 to 65 microteslas).