The operator of the imager gives input to the computer through a control console. An imaging sequence is selected and customized from the console. The operator can see the images on a video display located on the console or can make hard copies of the images on a film printer. The next three sections of this chapter go into more detail on the magnet, gradient coils, RF coils, and RF detector on magnetic resonance imagers. The imaging magnet is the most expensive component of the magnetic resonance imaging system.
Most magnets are of the superconducting type.
This is a picture of a 1.5 Tesla superconducting magnet from a magnetic resonance imager. A superconducting magnet is an electromagnet made of superconducting wire. Once current is caused to flow in the coil it will continue to flow as long as the coil is kept at liquid helium temperatures. The next animation window contains a cross sectional view of a superconducting imaging magnet. The length of superconducting wire in the magnet is typically several miles.