From 65438 to 0946, Flex Bloch of Stanford University and Edward purcell of Harvard University independently discovered the phenomenon of nuclear magnetic resonance.
When the spinning nucleus is radiated by radio frequency in a constant magnetic field, when the radio frequency is equal to the precession frequency of the nucleus in a constant magnetic field, the phenomenon of * * * vibration absorption will occur.
Raymond Damadian, an American, filed a patent application on1March 7, 972, and obtained the U.S. Patent No.3,789,832 on February 5, 974. He applied magnetic resonance imaging to medical clinical examination and invented magnetic resonance imaging (MRI).
Extended data:
Magnetic resonance imaging provides a large amount of information, clear and fine images, high resolution and good contrast, which can be used for quantitative analysis, especially for horizontal display of soft tissues.
It can also directly make cross-sectional, sagittal, coronal and various inclined plane sectional images, without artifacts, without injection of contrast agent, and without adverse effects on the body. At present, it has been widely used in clinic, and the diagnosis of some diseases has become an indispensable means of examination.
1970, Raymond Damandian found that under the condition of magnetic excitation, the effects of nuclear magnetic resonance vibration on the nuclei of healthy cells and cancer cells are different, and it takes much longer for them to return to equilibrium from high energy state. This discovery laid the foundation for filing a patent application for magnetic resonance imaging.
People's Network-Patented magnetic resonance imaging affects the world