Developed by GE Lunar; the ARTOSCANâ„¢-M is designed specifically for in-office musculoskeletal imaging. ARTOSCAN-M's compact, modular design allows placing within a clinical environment, bringing MRI to the patient. Patients remain outside the magnet at all times during the examinations, enabling constant patient-technologist contact. ARTOSCAN-M requires no special RF room, magnetic shielding, special power supply or air conditioning.
The C-SCANâ„¢ (also known as Artoscan C) is developed from the ARTOSCANâ„¢ - M, with a new computer platform.

Quick Overview
Please note that there are different common names for this artifact.

During frequency encoding, fat protons precess slower than water protons in the same slice because of their magnetic shielding. Through the difference in resonance frequency between water and fat, protons at the same location are misregistrated (dislocated) by the Fourier transformation, when converting MRI signals from frequency to spatial domain. This chemical shift misregistration cause accentuation of any fat-water interfaces along the frequency axis and may be mistaken for pathology. Where fat and water are in the same location, this artifact can be seen as a bright or dark band at the edge of the anatomy.
Protons in fat and water molecules are separated by a chemical shift of about 3.5 ppm. The actual shift in Hertz (Hz) depends on the magnetic field strength of the magnet being used. Higher field strength increases the misregistration, while in contrast a higher gradient strength has a positive effect. For a 0.3 T system operating at 12.8 MHz the shift will be 44.8 Hz compared with a 223.6 Hz shift for a 1.5 T system operating at 63.9 MHz.

For artifact reduction helps a smaller water fat shift (higher bandwidth), a higher matrix, an in phase TE or a spin echo technique. Since the misregistration offset is present in the read out axis the patient may be rescanned with this axis parallel to the fat-water interface. Steeper gradient may be employed to reduce the chemical shift offset in mm. Another strategy is to employ specialized pulse sequences such as fat saturation or inversion recovery imaging. Fat suppression techniques eliminate chemical shift artifacts caused by the lack of fat signal.

See also Black Boundary Artifact and Magnetic Resonance Spectroscopy.

O-scan is manufactured and distributed by Esaote SpA
O-scan is a compact, dedicated extremity MRI system designed for easy installation and high throughput. The complete system fits in a 9' x 10' room, doesn't need for RF or magnetic shielding and it plugs in the wall. The 0.31T permanent magnet along with dual phased array RF coils, and advanced imaging protocols provide outstanding image quality and fast 25 minute complete examinations.
Esaote North America is the exclusive distributor of the O-scan system in the USA.

Radio frequency shielding includes the construction of enclosures for the purpose of reducing the transmission of electric or magnetic fields from one space to another (Faraday cage, Faraday shield). Electrically conducted shielding is designed to isolate MRI systems from its environment at the resonant frequencies.
All electronic and computer systems radiate certain frequencies of radio and magnetic waves. They can interfere with other equipment in the vicinity. Magnetic shielding enclosures are used to reduce the levels of RF radiation that enters or leaves the shielded room.
Copper shielding enclosures are designed to filter a range of frequencies under specified conditions. One of the characteristics of copper is its high electrical conductivity. Also its other physical properties like ductility, malleability, and ease of soldering, make it an ideal material for radio frequency shielding. Sheet copper can be formed into any shape and size, and electrically connected to a grounding system to provide an effective RF shielding.

See also MRI Safety

See Magnetic Shielding, Cryoshielding and Faraday Shield.