MR Imaging

Question 1

How does the MR scanner work?

Answer 1

Uses Magnetic Field Strength

Question 2

MRI definition

Answer 2

Magnetic Resonance Imaging (MRI)

MR scanner enables us to view 3D images of internal body structures
Patients are placed within a large, static magnetic field.

The nuclei of certain atoms possess a spin- this induces a magnetic field around that nucleus. These then act similar to a bar magnet.

When placed in an external magnetic field (i.e. MRI scanner) the atoms align with that field.

Like a gyroscope the nuclei ‘precess’ at a certain frequency (rotations per second) this depends on the strength of the magnetic field.

The frequency is known as the Larmor Frequency

If a radio frequency is applied to these precessing nuclei, they can be ‘knocked’ out of alignment by 90 degrees