Why is MRI So Loud?
If we like to enter inside our body and observe what is all happening it is possible with magnetic resonance imaging (MRI) both for doctors as well as the patients. MRI scanning is really a boon to the human society for diagnosing many disorders and helps the doctors for giving the patients optimal treatment. It is today considered a standard diagnostic technology available since its invention about 27 years ago. People taking MRI scan say that it makes so much sound while operating.
The magnetic field gradients in the MRI scanning process are trapped as rapid pulses into the computer to create 3-dimensional images of the region of body in the patient. The electric field creates magnetic pulses that are transient and not permanent. It is generated when the machine is running. There is also static magnetic field created strongly by the magnets in the machine. Essentially there are two magnetic fields created which are facing in opposite directions. These two magnetic fields generate a torque which will try to arrange the magnetic fields in one proper direction.
Both the static magnetic field as well as the dynamically generated magnetic field is strong enough to develop mechanical vibrations which are the cause for the loud sound that is heard. The magnetic resonance imaging works with the heavy powered super electromagnet that resonate at specific frequencies based on the region of the body and the organ which is being scanned.
The electric coils that are placed within the main big magnet release magnetic pulses which are equally strong compared to that of magnetic field from the big magnet. As the distance between the magnetic field of actual magnet and that of electric field generated magnetic pulses cannot be changed, the gradient pulse will touch the big magnetic field which starts a strong force that result in vibrations. As the strength of the electric field gradient and main magnetic field is more, the sound made by the MRI machine will also be more.