Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, United States of America.
Systems Engineering and Computer Science Program, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Phys Med Biol. 2024 Jun 24;69(13). doi: 10.1088/1361-6560/ad5510.
. Image reconstruction is a fundamental step in magnetic particle imaging (MPI). One of the main challenges is the fact that the reconstructions are computationally intensive and time-consuming, so choosing an algorithm presents a compromise between accuracy and execution time, which depends on the application. This work proposes a method that provides both fast and accurate image reconstructions.. Image reconstruction algorithms were implemented to be executed in parallel in(GPUs) using the CUDA framework. The calculation of the model-based MPI calibration matrix was also implemented in GPU to allow both fast and flexible reconstructions.. The parallel algorithms were able to accelerate the reconstructions by up to about6,100times in comparison to the serial Kaczmarz algorithm executed in the CPU, allowing for real-time applications. Reconstructions using the OpenMPIData dataset validated the proposed algorithms and demonstrated that they are able to provide both fast and accurate reconstructions. The calculation of the calibration matrix was accelerated by up to about 37 times.. The parallel algorithms proposed in this work can provide single-frame MPI reconstructions in real time, with frame rates greater than 100 frames per second. The parallel calculation of the calibration matrix can be combined with the parallel reconstruction to deliver images in less time than the serial Kaczmarz reconstruction, potentially eliminating the need of storing the calibration matrix in the main memory, and providing the flexibility of redefining scanning and reconstruction parameters during execution.
图像重建是磁共振粒子成像(MPI)的基本步骤之一。主要挑战之一是重建计算密集且耗时,因此选择算法需要在准确性和执行时间之间做出折衷,具体取决于应用。本工作提出了一种既能快速又能准确重建图像的方法。
我们使用 CUDA 框架在(GPU)上实现了并行执行的图像重建算法。还在 GPU 上实现了基于模型的 MPI 校准矩阵的计算,以实现快速灵活的重建。
与在 CPU 上执行的串行 Kaczmarz 算法相比,并行算法能够将重建速度提高约 6100 倍,从而实现实时应用。使用 OpenMPIData 数据集进行的重建验证了所提出的算法,并证明它们能够提供快速准确的重建。校准矩阵的计算速度最多可提高约 37 倍。
本文提出的并行算法可以实时提供单帧 MPI 重建,帧率大于每秒 100 帧。校准矩阵的并行计算可以与并行重建相结合,在比串行 Kaczmarz 重建更短的时间内提供图像,有可能消除在主存中存储校准矩阵的需求,并在执行过程中提供重新定义扫描和重建参数的灵活性。