Magnetic resonance system with radio-frequency shield with frequency-dependent shielding effect

US7642780B2 · kind B2 · utility

Assignees

• Siemens Aktiengesellschaft · DE
• FRIEDRICH-ALEXANDER-UNIVERSITÄT ERLANGEN-NÜRNBERG · DE

Inventors

• Dirk Diehl · Erlangen, DE
• Wolfgang Renz · Erlangen, DE
• Lorenz-Peter Schmidt · Prüm, DE
• Ulrich Von Knobloch · Munich, DE

Key dates

• Filing date: Mar 21, 2008
• Grant date: Jan 5, 2010
• Expiry date: Jul 5, 2028

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/34046
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A magnetic resonance system has a basic magnet that generates a static basic magnetic field in an examination volume, and a whole-body antenna that emits a homogeneous radio-frequency field in the examination volume, the homogeneous radio-frequency field exhibiting an excitation frequency so that nuclei in an examination subject in the examination volume are excited to emit magnetic resonance signals, and a radio-frequency shield. The radio-frequency shield is arranged between the whole-body antenna and the basic magnet. The whole-body antenna is arranged between the radio-frequency shield and the examination volume. The radio-frequency shield is fashioned to exhibit a high shielding effect in a shielding frequency range that encompasses the excitation frequency. The shielding effect drops to a significantly lower shielding effect on both sides at side bands adjoining the shielding frequency range. The shielding frequency range and the side bands exhibit bandwidths that are significantly smaller than the excitation frequency.