A kind of SAR real-time monitoring system and method of multi-channel magnetic resonance imaging equipment

Abstract

The invention relates to an SAR (Specific Absorption Rate) real-time monitoring system and method of multi-channel magnetic resonance imaging equipment. The SAR real-time monitoring system is characterized in that the monitoring system comprises a plurality of power measuring units and a digital signal processing unit, each power measuring unit comprises a two-way directional coupler, a forward power sensor and a backward power sensor; the digital signal processing unit comprises a plurality of analog to digital conversion modules, a microprocessor and a memory; each power measuring unit is arranged between a transmitting and receiving switch and a radio-frequency transmitting coil of each channel in the magnetic resonance imaging equipment, measures instantaneous feed-through power of the channel and transmits the measurement result to the digital signal processing unit; the digital signal processing unit processes the received measurement result and then outputs and transmits a control signal to a control spectrometer, and amplifiers of corresponding channels are kept on or off by the control spectrometer. The SAR real-time monitoring system and method can be widely applied to magnetic resonance imaging equipment for purposes of clinical diagnosis or scientific research.

Description

technical field [0001] The invention relates to a monitoring system and method for electromagnetic wave energy absorption rate, in particular to a real-time monitoring system and method for electromagnetic energy absorption rate SAR (Specific Absorption Rate) of a multi-channel magnetic resonance imaging device. Background technique [0002] Magnetic resonance imaging is an imaging method that can produce internal images of the human body without radiation and other ionizing radiation. It is widely used in clinical medicine and basic science, including biomedicine, genetics, neuroscience, psychology, cognitive science, etc. field. The working principle of magnetic resonance imaging is roughly as follows: the magnet generates a relatively uniform basic magnetic field with strong magnetic field strength, that is, the main magnetic field B 0 field, and then superimpose a three-dimensional gradient magnetic field for spatial position encoding on the main magnetic field. In mag...

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Problems solved by technology

For some uniformly excited coils in different media, the maximum value of the local RF energy absorption rate is close to 1.2 to 5 times of the overall RF energy absorption rate. When the traditional monitoring method is used to monitor the SAR value of the human body, the obtained local RF energy absorption rate The estimation range is too high, resulting in some radio frequency sequences cannot operate in high field, which is a great waste; and for coils with very uneven emission, traditional monitoring methods are not enough to ensure that the local radio frequency energy absorption rate does not exceed the safety standard

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