Physics of magnetic resonance imaging

Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to investigate the anatomy and physiology of the body and the physics of the technique involves the interaction of matter with electromagnetic fields. The human body is largely composed of water molecules, each containing two hydrogen nuclei, or protons. When inside the magnetic field (B₀) of the scanner, the magnetic moments of these protons align with the direction of the field.