MAGNETIC RESONANCE IMAGING SCANNER WITH MOLDED FIXED SHIMS

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 main 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).