The Fundamental Physics of MRI

      Magnetic Resonance Imaging (MRI) is a direct application of magnetic physics, quantum physics, Faraday’s Law, and Fourier analysis for medical use.  When protons in a patient are exposed to a magnetic field, due to their magnetic dipole moment, they will line up with the magnetic field.  An electromagnetic wave is then used to move the protons into a superposition of the two allowed states as dictated by quantum mechanics.  While in the superposition, the protons precess creating a rotating magnetic field causing a time dependent signal due to Faraday’s Law.  The signal can then be turned into a detailed image of the internal structures of the body using a mathematical technique, the Fourier transform.  Together these scientific elements create a revolutionary tool for the field of medicine.