Gradient system and gradient magnetic field control method and MRI (magnetic resonance imaging) system

Abstract

The invention provides a gradient system and a gradient magnetic field control method and an MRI (magnetic resonance imaging) system. The gradient system based on current magnetic flux double closed loop control at least comprises a detecting module, a first comparator, a first adjuster, a second comparator, a gradient coil, a sensor and a gradient amplifier, wherein the detecting module is used for detecting and feeding back corresponding induced electromotive force according to variation of magnetic flux of the gradient magnetic field, the sensor is connected with the gradient coil and used for detecting and feeding back gradient current, the gradient amplifier is connected with the second comparator, the gradient coil and the sensor and used for amplifying current error obtained after comparing control current outputted by the second comparator with the gradient current fed back by the sensor so as to drive the corresponding gradient current of the gradient coil, and accordingly, the gradient magnetic field is controlled. By the gradient system based on the current magnetic flux double closed loop control, automatic compensation of eddy current loss is realized, and control of the gradient magnetic field is more accurate.

Description

technical field [0001] The invention relates to the technical field of nuclear magnetic resonance imaging, and mainly relates to a gradient system based on double closed-loop control of current and magnetic flux, specifically a gradient system, a gradient magnetic field control method, and a nuclear magnetic resonance imaging system. Background technique [0002] MRI (Magnetic Resonance Imaging, MRI) is an imaging technique that uses the resonance characteristics of the magnetic nucleus of a living body in a magnetic field for imaging. It has the characteristics of no ionizing radiation, no damage, high resolution, high contrast, multi-parameter imaging, and cross-sectional imaging in any orientation, and has been widely used in the field of medical imaging. [0003] The MRI system is mainly composed of a magnet system, a gradient system, a radio frequency system, and a signal acquisition and image reconstruction system. Among them, the magnet system is used to provide a un...

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Problems solved by technology

[0007] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a gradient system, a gradient magnetic field control method, and a magnetic resonance imaging system, which are used to solve the problem of gradient current compensation in the prior art only through gradient amplifiers off-line. The problem of low control precision

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