2006-06-14 06:33:40 · 4 answers · asked by rachellynn200 5 in Health ➔ Other - Health
The name magnetic resonance imaging is not the original name of MRI. It was originally called a NRI for nuclear resonance imaging. The company that first made them didn't want people to think it was a nuclear reaction so they changed the name to magnetic. It is not a nuclear reaction though, an MRI sends out very strong oscillating magnetic fields. Every atom in the universe and in your body has a nucleus, and the nucleus has its own oscillating magnetic field. The magnetic field from the MRI machine interacts with all the little tiny magnetic fields of the atoms and lines them up in the same direction, then can tell the density of it by the density of the atomic nuclei. The sound you hear from the MRI machine is two fold. First the magnetic fields are not made by actual magnets, they are electromagnets that run huge currents in circles to create the magnetic fields. The currents are so big that some of the energy is given off as heat and sound. This is the loud buzzing sound you hear, similar to buzzing power lines. The second noise is all the motors that move the electromagnet around so it can look at different parts of the body and different angles. The electromagnet is very heavy so the motors strain a lot to move it around, creating a lot of noise.
2006-06-14 07:06:12 · answer #1 · answered by mrchinlersir 5 · 5⤊ 1⤋
back2skewl, LOL :)
# Acoustic noise: Loud noises and vibrations are produced by forces resulting from rapidly switched magnetic gradients interacting with the main magnetic field. This is most marked with high-field machines and rapid-imaging techniques in which sound intensity can reach 130 dB (equivalent to a jet engine at take-off). Appropriate use of ear protection is essential. Manufacturers are now incorporating noise insulation and active noise cancellation systems on their equipment.
2006-06-14 06:41:28 · answer #2 · answered by ringm 3 · 0⤊ 0⤋
Because the Magnet is being hit to send out the Sound waves through you body and echo back to the machine. That is why is is called Magnetic Resonnance(sound) Imaging. it gets a very good picture of your body
2006-06-14 06:38:22 · answer #3 · answered by back2skewl 5 · 0⤊ 0⤋
because of the giant hamster-wheel that generates the power.
2006-06-14 06:47:25 · answer #4 · answered by spryguy1978 1 · 0⤊ 0⤋