Nuclear magnetic resonance imaging was first described in 1946 and used to determine the structure of complex molecules.
Magnetic resonance imaging (MRI) is a medical test to make pictures of structures and organs inside the body. This test generates the reports of various part of the body such as head, chest, blood vessels, abdomen and pelvis, bones and joints, and spine.
MRI Process:
The process of MRI is dependent on the free protons in the hydrogen nuclei in molecules of water (H2O). Because water is present in almost all biological tissues, the hydrogen proton is ideal. The protons within a patient's hydrogen nuclei should be regarded as small bar magnets, which are randomly oriented in space. The patient is placed in a strong magnetic field, which aligns the bar magnets. When a pulse of radio waves is passed through the patient the magnets are deflected, and as they return to their aligned position they emit small radio pulses. The strength and frequency of the emitted pulses and the time it takes for the protons to return to their pre-excited state produce a signal. These signals are analyzed by a powerful computer, and an image is created.