Why do MRIs always have to have strong magnets?
MRI stands for Magnetic Resonance Imaging To understand how MRI works, let’s start by focusing on the “magnetic” in MRI. The biggest and most important component in an MRI system is the magnet. The magnet in an MRI system is rated using a unit of measure known as a tesla. Another unit of measure commonly used with magnets is the gauss (1 tesla = 10,000 gauss). The magnets in use today in MRI are in the 0.5-tesla to 2.0-tesla range, or 5,000 to 20,000 gauss. Magnetic fields greater than 2 tesla have not been approved for use in medical imaging, though much more powerful magnets — up to 60 tesla — are used in research. Compared with the Earth’s 0.5-gauss magnetic field, you can see how incredibly powerful these magnets are. Numbers like that help provide an intellectual understanding of the magnetic strength, but everyday examples are also helpful. The MRI suite can be a very dangerous place if strict precautions are not observed. Metal objects can become dangerous projectiles if they
