Method and system for measuring and correcting imaging magnetic field in magnetic resonance device

Abstract

A method and a system for measuring and calibrating an imaging magnetic field in a magnetic resonance apparatus are provided. The method includes: providing the imaging magnetic field, where the imaging magnetic field is adapted for scanning an object; sampling a signal corresponding to the imaging magnetic field; processing the signal to obtain an actual magnetic field intensity; and calibrating based on a difference between the actual magnetic field intensity and a target magnetic field intensity. The system includes: a magnetic component, adapted for scanning an object to be imaged; a sampling unit, adapted for sampling a signal corresponding to the imaging magnetic field; a processing unit, adapted for processing the signal to obtain an actual magnetic field intensity; a calibration unit, adapted for calibrating based on a difference between the actual magnetic field intensity and a target magnetic field intensity; and a control unit, adapted for controlling the system.

Description

technical field [0001] The invention relates to magnetic resonance technology, in particular to a method and system for measuring and correcting an imaging magnetic field in a magnetic resonance device. Background technique [0002] Magnetic Resonance Imaging (MRI) usually consists of five parts: superconducting coils, gradient coils, radio frequency coils, computer systems and other auxiliary equipment. [0003] Among them, the superconducting coil is the main device for generating the imaging magnetic field, and the gradient coil can provide the gradient field, and the gradient field cooperates with the main imaging magnetic field to form an imaging magnetic field (abbreviated as B for magnetic resonance detection). 0 field). The radio frequency coil includes a transmitting coil and a receiving coil, among which the body coil is the main transmitting coil. The transmitting coil emits radio frequency pulses to excite protons in the human body to resonate. The receiving c...

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Problems solved by technology

[0007] In addition to inhomogeneity, the stability of the imaging magnetic field itself is also an important factor to consider. The stability of the imaging magnetic field is divided into thermal stability and time stability. The gradient coil that generates the gradient imaging magnetic field dissipates a large amount of heat, which may cause In addition, the temperature of the warm hole of the magnet may also rise due to eddy currents. The increase in temperature will easily lead to changes in the magnetic permeability, which will cause the imaging magnetic field to drift and have a negative impact on the image quality. In the Chinese patent CN101427919C, a technical solution for avoiding imaging magnetic field drift by controlling temperature changes is proposed

[0008] However, the non-ideal state of the imaging magnetic field mentioned above is either to add a large number of additional hardware devices to control the non-ideal state, or to correct the image during the post-processing of the magnetic resonance. The imaging magnetic field correction scheme is not ideal enough. The image quality obtained by the resonance device is not high enough

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