Shenyang Neusoft Medical Systems Co., Ltd.

Shanghai Neusoft Medical Technology Co., Ltd.

Rong Sun

Yan Wang

Hongwei Wang

Qin Xu

Jianhua Shi

Lin Wu

Haiquan Li

Junwei Shang

Methods, systems, and computer-readable storage mediums for correcting time in a nuclear magnetic resonance device are provided. In one aspect, a method includes obtaining respective transmission time delays of three gradient pulse signals that are generated by a three-dimensional gradient subsystem of the nuclear magnetic resonance device and include a slice-selection gradient signal, a phase-encoding gradient signal, and a frequency-encoding gradient signal, determining a time correction value according to the obtained respective transmission time delays of the three gradient pulse signals, and correcting a respective output time of each of the three gradient pulse signals, an output time of a radio-frequency (RF) pulse signal generated by a RF transmitting subsystem of the nuclear magnetic resonance device, and a reception time of a magnetic resonance signal received by a RF receiving subsystem in a scanning cycle according to the determined time correction value.

Correcting time

Methods of generating a gradient signal, gradient signal generators and magnetic resonance imaging systems are provided. In one aspect, a method includes obtaining a target amplitude and a target duration associated with a target precision corresponding to the gradient signal; generating a first actual amplitude by intercepting the target amplitude according to an actual precision of a DAC; generating a second actual amplitude according to the first actual amplitude, wherein a difference between the second actual amplitude and the first actual amplitude is 1; determining a first actual duration of outputting the first actual amplitude and a second actual duration of outputting the second actual amplitude according to the target amplitude, the target duration, the first actual amplitude and the second actual amplitude; controlling the DAC to output the first actual amplitude according to the first actual duration and output the second actual amplitude according to the second actual duration.

Generating gradient signal

Methods of generating a gradient waveform, gradient waveform generators and magnetic resonance imaging systems are provided. In one aspect, a first digital value is obtained by quantizing and coding spatial position information of a voxel of a subject according to the number of preset quantization bits, wherein the number of the quantization bits are more than the number of allowed input bits for a DAC; a second digital value is determined to be inputted into the DAC according to the first digital value and the number of the allowed input bits for the DAC; a quantization error is determined according to the first digital value and the second digital value; an error accumulating value is updated by accumulating the quantization error to the error accumulation value; the second digital value corrected according to the error accumulation value; and the corrected second digital value is inputted into the DAC.

Generating gradient waveform

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Shenyang, China

Rong Sun