Medical Research Poster: MRI

Soft tissue contains water molecules and the magnetic field acts upon microscopic substances (called protons) found in water. The magnetised protons in the soft tissue send out an echo in response to the MRI scan’s radio waves. A computer then organises these echoes into images.

Magnetic resonance imaging (MRI), three-dimensional diagnostic imaging technique used to visualize organs and structures inside the body without the need for X-rays or other radiation.

Most MRI systems use a superconducting magnet, which consists of many coils or windings of wire through which a current of electricity is passed, creating a magnetic field of up to 2.0 tesla. Maintaining such a large magnetic field requires a good deal of energy, which is accomplished by superconductivity,

The physics of MRI are complicated and much harder to understand than those underpinning image generation in plain radiography, CT or ultrasound.

What follows is a very abbreviated, 'broad strokes' description of the process. Essentially, the process can be broken down into four parts:

preparation
excitation
spatial encoding
signal acquisition