Magnetic resonance imaging scanner with molded fixed shims

US7495441B2 · kind B2 · utility

Assignee

• KONINKLIJKE PHILIPS ELECTRONICS NV · NL

Inventors

• William H. Amor · Chagrin Falls, US
• Dennis K. Everett · Seven Hills, US
• Jerome S. Alden · Aurora, US
• Robert G. Henderson · Wickliffe, US
• Terrence M. Doyle · Hudson, US
• Ronald B. Sharpless · Houston, US
• Gerardus B. J. Mulder · Best, NL
• Gerardus N. Peeren · Eindhoven, NL

Key dates

• Filing date: Apr 19, 2004
• Grant date: Feb 24, 2009
• Expiry date: Dec 6, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/3873
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

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).