The History of MRI

- Sir Joseph Larmor developed the equation that the angular frequency of precession of the nuclear spins being proportional to the strength of the magnetic field

- In the 1930 Isidor Isaac Rabi succeeded in detecting and measuring single states of rotation of atoms and molecules, and in determining the mechanical and magnetic moments of the nuclei.

- Felix Bloch and Edward Purcell developed instruments, whiche could measure the magnetic resonance in bulk material such as liquids and solids ,the both honored with the Nobel Prize for physics in 1952

- In the early of 70 s ,Raymond Damadian demonstrated with his NMR device, there are different T1relaxation times between normal and abnormal tissues of the same type, as well as between different types of normal tissues

-in 1973, Paul Lauterbur described a new imaging technique that he termed Zeugmatography. By utilizing gradients in the magnetic field ,this technique was able to produce a two-dimensional image

Peter mansfield further developed the utilization of gradients in te magnetic field and the mathematically analysis of these signals for a more useful imaging technique .

Paul Lauterbur and Peter Mansfield were awarded with the 2003 Nobel Prize in Medicine.

- In 1975, Richard Ernst introduced 2D NMR usin phase and freuency encoding, and the Fourier Transform . instead of Paul Lauterbur back-projection,he timely switched magnetic field

1977/78 First images could be presented. Across section through a finger by Peter Mansfield and Andrew A. Maudsley. Peter Mansfield also could present the first image through th abdomen.

In 1977, Raymond Damadian completed after 7 years the first MR scanner . In 1978, he founded the FONAR Corporation, which manufactured the first commercial MRI scanner in 1980.Fonar went public in 1981.

1981: schering submitted a patent application for Gd-DTPA dimeglumine.

1982: the first magnetization -transfer imaging by Robert N.Muller.

In 1983, Toshiba obtained approval from the Ministry of ealth and Welfare in japan for the first commercial MRI system.

In 1984, FONAR Corporation receives FDA approval for its first MRI scanner.

1986: Jurgen Hennig, A. Nauerth, and Hartmut Friedburg introduced rapid acquisition with relaxation enhancement imaging. Axel Haase, Jens Frahm, Dieeter Matthaei, Wolfgang Haenicke, and Dietmar K. Merboldt developed the FLASH fast low angle shot sequence.

1988: scherings MAGNEVIST gets its first approval by FDA.

In 1991, fMRI was developed independently by the University of Minnesotas Center for MR Research and Massachusetts General Hospital MR Center.

From 1992 to 1997 Fonar was paid for the infringement of its patents from nearly every one of its competitors in the MRI industry including giant multi-nationals as Toshiba, Siemens, Shimadzu, Philips, and GE.