Where is the magnetic field in a MRI?

In magnetic resonance imaging (MRI), the magnetic field is generated by a large, powerful magnet. This magnet is made of superconducting wire, which allows it to create a very strong magnetic field without using a lot of electricity. The magnet is typically located inside the MRI scanner, and the patient lies on a table that is moved into the magnet's field.

The magnetic field in an MRI scanner is very strong, typically ranging from 1.5 to 3 Tesla. This is much stronger than the Earth's magnetic field, which is only about 0.5 Gauss. The strong magnetic field in an MRI scanner is what allows it to create detailed images of the human body.

When a patient is placed in the MRI scanner, the magnetic field causes the protons in their body to align with the magnetic field. This creates a net magnetization of the body. When a radiofrequency pulse is then applied to the patient, the protons flip their spins and this creates a measurable signal. This signal is then used to create an image of the patient's body.

The magnetic field in an MRI scanner is essential for creating images of the human body. Without the magnetic field, the protons in the body would not align and there would be no signal to create an image.