摘要:
The invention relates to a treatment room (7) suitable for recording images of a human or animal body on the basis of a magnetic resonance (MR) imaging technique, the walls (7a), the ceiling (7b) and the floor (7c) of the treatment room forming an electromagnetic shield for a magnetic resonance (MR) imaging system (1) arranged in the treatment room, which MR imaging system comprises at least a target area (5) in which a human or animal body can be placed, a housing (2, 3, 4) comprising at least one main magnetic unit and at least one gradient magnetic unit for generating one or more magnetic fields in the target area (5), and at least one radio-frequency (RF) pulse unit (6) for generating an electromagnetic RF pulse in the target area (5). The invention further relates to a magnetic resonance imaging system comprising a target area in which a human or animal body can be placed, a housing comprising at least one main magnetic unit and at least one gradient magnetic unit for generating one or more magnetic fields in the target area, and at least one radio-frequency (RF) pulse unit for generating an electromagnetic RF pulse in the target area. In accordance with the invention, means (10, 11, 12, 13, 14, 15, 16, 17) are present which, in operation, counteract the electromagnetic effects (8) of the RF pulse in the treatment room (7) outside the target area (5).
摘要:
A magnetic resonance imaging scanner includes a generally cylindrical main magnet assembly (10) that defines a cylinder axis (16). A first set of shims (60) are rigidly positioned inside the magnet assembly (10) at about a first distance (d1) relative to the cylinder axis (16). A second set of shims (62) are rigidly positioned inside the main magnet assembly (10) at about a second distance (d2) relative to the cylinder axis (16). The second distance (d2) is different from the first distance (d1). A generally cylindrical radio frequency coil (26) is arranged inside the main magnet assembly (10) at about a third distance (d3) relative to the cylinder axis (16). A plurality of gradient coils (20) are arranged inside the main magnet assembly (10) at about a fourth distance (d4) relative to the cylinder axis (16).
摘要:
The invention relates to a magnetic resonance imaging (MRI) system having an open superconducting magnet system (1), which comprises a number of horizontally oriented superconducting coils (3-10) and a cryogenic container (11) for containing a liquid cooling medium for cooling the superconducting coils which are located within the cryogenic container. At its top, the cryogenic container is provided with a recondensor (23) for continuously liquefying the cooling medium. The magnet system has a circuit for guiding the liquid cooling medium from the recondensor along at least part of the superconducting coils.