Zhonghao Zhang; Ming Lu; Hao Liang; Zhongliang Zu; Yi Gu; Xiao Wang; Yuankai Huo; Xinqiang Yan (2026)..Magnetic Resonance Imaging, 129, 110644.
This study focuses on improving how passive resonators—devices used in MRI scanners to shape and strengthen radiofrequency (RF) fields—are designed and optimized. Normally, designing these structures requiresfull-wave electromagnetic (EM) simulations, which model how RF fields behave in detail. While accurate, these simulations are extremely slow and computationally expensive, especially when many design variables (like different capacitor or inductor values) need to be tested.
To solve this problem, the researchers developed a faster method called aco-simulation framework, which combines a single detailed EM simulation with simpler circuit-level calculations. In this approach, parts of the resonator are replaced with connection points (“ports”) during the initial simulation, allowing many different electrical configurations to be tested afterward without repeating the costly EM computation. They also integrated agenetic algorithm(a search method inspired by natural selection) to automatically explore thousands of design options and find the best configuration for enhancing RF fields in a specific target area.
The method was tested in several scenarios, from simple models to a realistic human head model, and produced results nearly identical to full EM simulations (with less than 1% error). Importantly, the optimization process took less than five minutes, compared to what would normally require extremely long computation times. Overall, this approach offers a much faster and scalable way to design passive MRI components, making it easier to improve image quality without the heavy computational cost of traditional methods.

Fig. 1.Schematic diagram of the co-simulation principle. Incorporate the optimization stage, indicate the starting point of the method and reorganized the layout.