How does an MRI work, and why is it so noisy?
Question of the Month Answered by: Russ Jacobs, Ph.D., Member of the Beckman Institute, Biology Magnetic resonance imaging machines, or MRIs, use strong magnetic fields and radio waves to look inside a patient without the need for surgery or the use of damaging radiation such as X-rays. MRIs have become standard equipment in many hospitals over the last decade. When an MRI machine looks inside the body, what it really sees are water molecules. Because all parts of the body contain some water, MRIs can examine any part of a patient’s body. Water molecules consist of oxygen and hydrogen atoms, and the core of a hydrogen atom–its nucleus–is a single proton. These protons have a basic, inherent property called nuclear spin. One way to think about this nuclear spin is that the protons actually spin like a gyroscope or a top. Because the protons also have an electrical charge, the spin makes them act like tiny magnets.
Question of the Month Answered by: Russ Jacobs, Ph.D., Member of the Beckman Institute, Biology Magnetic resonance imaging machines, or MRIs, use strong magnetic fields and radio waves to look inside a patient without the need for surgery or the use of damaging radiation such as X-rays. MRIs have become standard equipment in many hospitals over the last decade. When an MRI machine looks inside the body, what it really sees are water molecules. Because all parts of the body contain some water, MRIs can examine any part of a patient’s body. Water molecules consist of oxygen and hydrogen atoms, and the core of a hydrogen atom—its nucleus—is a single proton. These protons have a basic, inherent property called nuclear spin. One way to think about this nuclear spin is that the protons actually spin like a gyroscope or a top. Because the protons also have an electrical charge, the spin makes them act like tiny magnets. Scientists have found that a magnetic field will make the spinning proton
