A method for magnetic resonance gradient eddy current compensation
A gradient, one-way technology, applied in the direction of measuring magnetic variables, measuring devices, instruments, etc., can solve the problems of image artifacts, difficult eddy current field suppression, affecting image quality and diagnostic accuracy, and achieve the effect of improving the suppression effect.
Active Publication Date: 2017-05-24
EAST CHINA NORMAL UNIV +1
View PDF15 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
However, suppression of the short-term components of the eddy field becomes more difficult when the two techniques are combined
During fast imaging scanning, especially in the case of sharp switching of the gradient magnetic field, the influence of the short-term component of the eddy current field cannot be ignored, otherwise artifacts will appear in the obtained image, affecting image quality and diagnostic accuracy
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0029] see image 3 and Figure 4 , the present invention adds multiple reverse overshoot modules to the conventional gradient waveform generator, so that the time parameters and amplitude parameters of each reverse overshoot module are independently adjustable. In the signal chain, the front stage of the reverse overshoot module is a digital-to-analog converter, and the rear stage is a signal conditioning module. The reverse overshoot module is implemented by a differential circuit, a voltage divider circuit and a reverse follower. Among them, a potentiometer or a variable capacitor is used in the differential circuit to realize the adjustable time parameter of the reverse overshoot module, and a potentiometer is used in the voltage divider circuit to realize the adjustable amplitude parameter of the reverse overshoot module. The reverse overshoot module can also be implemented in the logic control unit of the gradient waveform generator. By modifying the value of the inter...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a compensation method for magnetic resonance gradient eddy current, the method is as follows: a plurality of reverse overswing modules with independent adjustable time parameter and range parameter are formed on the common gradient waveform generator; and a switching switch is added in each gradient channel for switching the each gradient channel at the main coil mode, shielding coil mode and common mode; then, adjusting the parameter for each gradient channel under the main coil mode and the shielding coil mode; finally, recovering all gradient channels to the common mode, adopting the algorithm optimization for optimizing pre-emphasis parameter and reverse overswing parameter; the method can improve the inhibitory effect of short time component of eddy current field while combining the pre-emphasis technology and self-shielding technology and keep the inhibitory effect of long time component of eddy current field.
Description
technical field [0001] The invention relates to magnetic resonance imaging technology, in particular to a gradient eddy current compensation method. Background technique [0002] Magnetic resonance imaging technology has become a very useful tool in medical diagnosis. Magnetic resonance imaging instrument mainly includes the following parts: magnet subsystem, gradient subsystem, radio frequency subsystem, spectrometer subsystem and main computer. Among them, the magnet subsystem is used to generate the static magnetic field; the gradient subsystem is used to generate the gradient magnetic field for three-dimensional spatial positioning; the radio frequency subsystem is used to generate excitation signals and collect magnetic resonance signals; the spectrometer subsystem is mainly used to control the gradient subsystem and The radio frequency subsystem makes them work together in the imaging process; the main computer is mainly used to realize the functions of imaging scheme...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01R33/385G01R33/387
Inventor 宁瑞鹏胡坤李钰刘擘杨光谢海滨
Owner EAST CHINA NORMAL UNIV