In electromagnetism, the Faraday cage or shield is an application of Gauss's law, one of Maxwell's equations. Gauss's law describes the distribution of electrical charge on a conducting form, such as a sphere, a plane, a torus, etc. Intuitively, since like charges repel each other, charge will "migrate" to the surface of the conducting form, as described below. The application is named after physicist Michael Faraday, who built the first Faraday cage in 1836, to demonstrate his finding. A Faraday shield is used generally for any kind of electrostatic shielding.
In MRI, one use of the Faraday shield is the shielding of the scanning room, to block incoming radio frequency (RF) signals which would contaminate the send and received signals of the MRI scanner, and it suppresses RF signals, which would else pollute the environment around.

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

RF noise, which often appears as static on the image, can be caused by a medical device located anywhere in the MR procedure room. RF noise is a result of excessive electromagnetic emissions from the device that interference with the proper operation of the MR scanner. The interference is attenuated and aliased in the frequency direction.

In the first case try to eliminate the factor of disturbance, if the problem persists screen the magnet- and room shielding.

See also Signal to Noise Ratio.

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.

See Active Shielding.

Rate of cryogen (liquid helium) evaporation in superconducting magnets, usually measured in liters of liquid per hour. The boil off rate of cryogen increases during ramping of the magnet and with eddy currents induced in the cryoshields by pulsed field gradients. In calculating cryogen consumption additional transfer and filling losses have to be considered.

See also Cryoshielding and Helium.