 | Info
Sheets |
| | | | | | | | | | | | | | | | | | | | | | | | |
 | Out-
side |
| | | | |
|
| | | | | |  | Searchterm 'relaxation' was also found in the following services: | | | | |
|  |  |
| |
|
•
In the 1930's, Isidor Isaac Rabi (Columbia University) 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 (Stanford University) and Edward Purcell (Harvard University) developed instruments, which could measure the magnetic resonance in bulk material such as liquids and solids. (Both honored with the Nobel Prize for Physics in 1952.) [The birth of the NMR spectroscopy]
•
In the early 70's, Raymond Damadian (State University of New York) demonstrated with his NMR device, that there are different T1 relaxation times between normal and abnormal tissues of the same type, as well as between different types of normal tissues.
•
In 1973, Paul Lauterbur (State University of New York) 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 (back-projection). (Through analysis of the characteristics of the emitted radio waves, their origin could be determined.) Peter Mansfield further developed the utilization of gradients in the magnetic field and the mathematically analysis of these signals for a more useful imaging technique. (Paul C Lauterbur and Peter Mansfield were awarded with the 2003 Nobel Prize in Medicine.)
•
1977/78: First images could be presented.
A cross section through a finger by Peter Mansfield and Andrew A. Maudsley.
Peter Mansfield also could present the first image through the abdomen.
•
In 1977, Raymond Damadian completed (after 7 years) the first MR scanner (Indomitable). 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 Health and Welfare in Japan for the first commercial MRI system.
•
1986: Jürgen Hennig, A. Nauerth, and Hartmut Friedburg (University of Freiburg) introduced RARE (rapid acquisition with relaxation enhancement) imaging. Axel Haase, Jens Frahm, Dieter Matthaei, Wolfgang Haenicke, and Dietmar K. Merboldt (Max-Planck-Institute, Göttingen) developed the FLASH ( fast low angle shot) sequence.
•
1988: Schering's MAGNEVIST gets its first approval by the FDA.
•
In 1991, fMRI was developed independently by the University of Minnesota's Center for Magnetic Resonance Research (CMRR) and Massachusetts General Hospital's (MGH) MR Center.
•
From 1992 to 1997 Fonar was paid for the infringement of it's patents from 'nearly every one of its competitors in the MRI industry including giant multi-nationals as Toshiba, Siemens, Shimadzu, Philips and GE'.
| | | | | | | | | | | | |  Further Reading: | | Basics:
|
|
News & More:
| |
| |
| | | | | |
| |
|
(MT) Magnetization Transfer was accidentally discovered by Wolff and Balaban in 1989. Conventional MRI is based on the differences in T1, T2 and the proton density (water content and the mobility of water molecules) in tissue; it relies primarily on free (bulk) water protons. The T2 relaxation times are greater than 10 ms and detectable. The T2 relaxation times of protons associated with macromolecules are less then 1 ms and not detectable in MRI.
Magnetization Transfer Imaging (MTI) is based on the magnetization interaction (through dipolar and/or chemical exchange) between bulk water protons and macromolecular protons. By applying an off resonance radio frequency pulse to the macromolecular protons, the saturation of these protons is then transferred to the bulk water protons. The result is a decrease in signal (the net magnetization of visible protons is reduced), depending on the magnitude of MT between tissue macromolecules and bulk water. With MTI, the presence or absence of macromolecules (e.g. in membranes, brain tissue) can be seen.
The magnetization transfer ratio (MTR) is the difference in signal intensity with or without MT.
See also Magnetization Transfer Contrast. | | | |
• View the DATABASE results for 'Magnetization Transfer' (7).
| | | | | | Further Reading: | | Basics:
|
|
News & More:
| |
| |
| | | | | |
| |
|
| | | |
• View the DATABASE results for 'R1' (33).
| | | | |
| | | Searchterm 'relaxation' was also found in the following services: | | | | |
| | |
| |
|
| | | |
• View the DATABASE results for 'R2' (26).
| | |
• View the NEWS results for 'R2' (1).
| | | | |
| | | | | |
| |
|
| | | |
• View the DATABASE results for 'Superparamagnetic Contrast Agents' (12).
| | | | | | Further Reading: | News & More:
|
|
| |
| | | | |
| | | |
|
| |
 | Look
Ups |
| |
] and 75 definitions [
]
(.pdf)
Random Page
top
