Method and device for monitoring radio-frequency exposure in a magnetic resonance measurement

US7622921B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Joerg Ulrich Fontius · Fairview Avenue, DE
• Juergen Nistler · Erlangen, DE
• Wolfgang Renz · Erlangen, DE
• Franz Schmitt · Erlangen, DE
• Karsten Wicklow · Erlangen, DE

Key dates

• Filing date: Dec 28, 2007
• Grant date: Nov 24, 2009
• Expiry date: Apr 8, 2028

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R33/288
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In a method and device for monitoring the physiologically effective radio-frequency exposure in at least one specific volume region of an examination subject in a magnetic resonance data acquisition scan in a magnetic resonance system, amplitude values are acquired that respectively represent, at specific acquisition points in time, a signal amplitude of the radio-frequency signals emitted or to be emitted via the radio-frequency signal channels. Also, phase values are acquired that represent the phases of the appertaining radio-frequency signals at these points in time. Local exposure values are then determined on the basis of the amplitude values and phase values, respectively representing a physiological exposure that the radio-frequency pulses cause at the examination subject at a specific location at a specific time. Based on this, exposure control values are determined that are compared with predetermined exposure limit values. When an exposure limit values is reached or exceeded, a control signal is output.