Abstract: In magnetic resonance imaging (MRI), a gradient preemphasis module with more compensation channels and adjustable parameters is often desired for better imaging quality and faster imaging speed. With the conventional design, however, a high performance preemphasis module often requires high resource consumption such that the field programmable gate array (FPGA) may encounter huge resource overhead. In this study, a new gradient preemphasis implementation scheme based on time-division multiplexing was proposed. With the new design, an 11 channels×4 sets of parameters implementation could be achieved with only 1/44 of the resources required by the conventional scheme. To test the performance of the new implementation, eddy current curves and magnetic resonance images before and after preemphasis compensation were measured on a 0.35 T scanner and compared. The results demonstrated that the module could effectively reduce eddy currents and related artifacts on the images.

Key words: magnetic resonance imaging (MRI), field programmable gate array (FPGA), gradient preemphasis, time-division multiplexing