MRI (Magnetic Resonance Imaging) is an imaging technique using magnetic energy. It is also called NMR (Nuclear Magnetic Resonance). This technique was discovered by Felix Bloch and Purcell in 1952. It has been used in the medical field.
In this technique, the body or part being examined is placed in a chamber surrounded by a powerful magnet and a special radio antennae. When the device is operating, magnetic field created by the magnet affects alignment and spin of certain types beta atoms with the living material. At the same time, a second rotating magnetic field is adjusted to cause particular kinds of atoms (such as hydrogen atoms in body fluids and various chemical compounds) to release weak radio waves with characteristics frequencies. The radio waves with characteristics frequencies. The radio waves are received by the antennae and are amplified. The amplified signals are then processed by a computer, and the computer generates a cross sectional image.
Uses of MRI
- It is used to examine joint injuries.
- it is used to detect slipped disc in the spinal column.
- It also shows the location of cancerous tumours within the breasts.
- It is used to detect tiny lesions of multiple sclerosis on brain and spinal cord.
- MRI does not employ ionizing radiations, hence it is free from radiations.
- It is used to study the tissue metabolism by spectroscopy.
- It is used to obtain sectional views in any plane like CT scan which is more or less restricted to cross sectional imaging.