Arrangement for operating a symmetrical radio-frequency antenna in a nuclear magnetic resonance tomography apparatus

US4922204A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Wilhelm Duerr · Erlangen, DE
• Ralph Oppelt · Uttenreuth, DE

Key dates

• Filing date: Mar 29, 1989
• Grant date: May 1, 1990
• Expiry date: Mar 29, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/3685
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

For operating the radio-frequency antenna of a nuclear magnetic resonance tomography apparatus, the antenna being connected to an asymmetrical line, a sheath wave trap is provided between the antenna and the line, with the inductor of the sheath wave trap being a toroid. A low-scatter sheath wave trap is obtained in this manner, particularly suitable for circularly polarized resonators. The trap suppresses difference currents caused by asymmetries, and thus simultaneously functions as a balanced-to-unbalanced transformer (balun).