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MRI History

MRI introduction MRI History MRI how it works MRI patient info

MRI involves lots of complex maths and physics and has taken the work of numerous scientists over many years to develop. It is based on a principle called nuclear magnetic resonance (NMR).

The first successful NMR experiment was made in 1946 independently by two scientists; Felix Bloch at Stanford University and Edward Purcell at Harvard University. They discovered that when nuclei from certain atoms were placed in a magnetic field they absorbed energy in the form of radio waves. This altered the equilibrium (stability) of the nuclei and as the nuclei returned to their original state they re-emitted the energy they had absorbed. Both scientists were awarded the Nobel Prize for physics in 1952 for their work. NMR had actually been observed in the late 1930’s by Professor Isidor Rabi, who had disregarded it thinking it was a false measurement of his experiment.

 Between 1950 -70 NMR was further developed. It was used for chemical and physical analysis of molecules. In the early 1970’s Dr. Raymond Damadian wanted to use NMR to separate healthy from cancerous tissue. In 1971 he showed that the signal that is emitted from hydrogen atoms using NMR in healthy tissue is different from the signal emitted in cancerous tissue.  This served as an drive for scientists motivating them to consider magnetic resonance for the detection of disease.

In 1973 Paul Lauterbur published a paper describing a new imaging technique, which would allow spatial localisation.  He demonstrated by showing NMR images of two test tubes. In 1977 Dr. Raymond Damadian demonstrated MRI of the whole body. In this same year Professor Peter Mansfield developed the echo planar imaging (EPI) technique. This technique was developed in later years was used to perform real-time movie imaging of the heart in 1987.

In the 1980’s as advances were made in the computer and magnet technology the scan time along with image quality improved of MRI improved. MRI began to be considered superior to CT for imaging certain tissues, such as the brain and spinal cord. The advantages MRI had over CT are that it does not involve ionising x-rays, it shows softer tissues in more detail, and it can produce images in any plane of the body.

 In 2003 Paul Lauterbur and Peter Mansfield were awarded the Nobel Prize for medicine for their work on MRI. Raymond Damadian was left out of the Noble prize to some controversy, as his although his achievements in MRI research were monumental.   

 Paul Lauterbur               Raymond Damadian

Further applications of MRI are MRI angiography, which is a technique used to study the heart and blood vessels. Functional MRI is a recent technique being used to study the human mind. This is where changes in the brain that occur upon different types stimulation can be viewed by MRI.

MRI of the brain and spinal cord
                                                                                                 
MRI Angiography of the blood vessels in the brain

MRI CT Refrences