From Siemens Medical Systems;
the MAGNETOM Rhapsody™. This open MRI system offers the proven image quality of 1.0 Tesla. In addition to the resulting broad range of applications, the open magnet of the high field system MAGNETOM Rhapsodyâ„¢ facilitates examination of claustrophobic and pediatric patients. And the system allows for expanded interventional applications.

From Siemens Medical Systems;
with the introduction of this system, it is possible to perform contrast MR angiography for abdominal, thoracic and neck vessels from the origins to the circle of Willis. The system also has many newer features including functional imaging, spectroscopy, advanced body, ortho- and neuroimaging.

The region surrounding a magnet and exhibiting a magnetic field strength, which is significantly higher than the earth's magnetic field (typically 0.05-0.1 mT, depending on geographical location). Initially the most magnets had very extensive fringe fields. Magnets with iron have reduced the fringe field substantially (passively shielded magnets). At least, adding appropriate additional superconducting coils to superconducting magnets has resulted in a drastic reduction of the extent of the fringe fields (actively shielded magnets).
Due to the physical properties of magnetic fields, the magnetic flux, which penetrates the useful volume of the magnet will return through the surroundings of the magnet to form closed field lines. Depending on the magnet construction, the returning flux will penetrate large open spaces (unshielded magnets) or will be confined largely to iron yokes or through secondary coils (shielded magnets).
Fringe fields constitute one of the major hazards of MR scanners as these fields acting over extended distances outside the magnet produce strong attractive forces upon magnetic objects. These can thus 'fly' into the magnet when loose nearby acting like projectiles. Fringe fields also exert unwanted forces on metallic implants in patients.

The mapping of the magnetic field by measuring or imaging the spatial distribution of magnetic field strength, can be performed by scanning with a probe and handles a large range of field strengths, but is slow and tedious. Accurate field maps can be made by measuring the Larmor frequency as a function of position.
The field must be homogeneous enough to allow MR imaging to be performed, than the magnetic field can be mapped by different methods.
1. The adaptation of chemical shift imaging.
2. The faster one measures the change in signal phase in an image obtained with a gradient echo pulse sequence resulting from a change in echo time TE, which is proportional to the local field strength.
Also useful is a spin echo pulse sequence with data collection from two time locations of the readout gradient and the data acquisition interval, where each having a known shift of the acquisition center away from the spin echo.

(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.