MRI梯度预加重模块的分时复用设计

为获得更优的成像质量和更快的成像速度，磁共振成像（MRI）系统的梯度预加重模块需要具有更多的补偿通道和调节参数，常规预加重模块的设计方案使现场可编程门阵列（FPGA）面临巨大的资源消耗.为解决高性能梯度预加重模块的资源消耗大的问题，本文提出了一种基于分时复用技术的梯度预加重实现方案，以常规方案1/44的资源实现了11通道×4组参数的梯度预加重模块.将该模块用于0.35 T MRI系统，测试了补偿前后的涡流曲线和磁共振图像，结果表明该模块有效降低了系统的涡流，减小了磁共振图像中的涡流伪影.

A Time-Division Multiplexing Design for Gradient Preemphasis Module in Magnetic Resonance Imaging Scanner

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.