Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:3701-3704. doi: 10.1109/EMBC46164.2021.9631111.
Magnetic Particle Imaging (MPI) is an emerging modality that images the magnetic nanoparticle distribution inside the body. The method is based on the non-linear response of the magnetic nanoparticles to an applied magnetic field. In this study, we present simulation results for three-dimensional (3D) tomographic imaging using an open-bore MPI system that can electronically scan a field free line (FFL). A field of view with 26×26×10 mm volume is imaged with a relatively low gradient field of 0.5 T/m. Imaging results for two 3D phantoms are presented: a letter phantom and a vessel phantom with stenosis regions. Using the system-matrix based reconstruction approach, the images were obtained with the Algebraic reconstruction technique (ART) and alternating direction method of multipliers (ADMM) methods. The stenosis regions were visually recognizable in high SNR conditions with ADMM. The effect of low gradient strength became prominent with increasing noise level, resulting in interlayer coupling artifacts.Clinical relevance- Magnetic Particle Imaging (MPI) is a new tracer-based imaging modality with high-spatiotemporal resolution. MPI can map quantitative distribution of super-paramagnetic iron oxide nanoparticles introduced inside the body. A field free line scanning MPI system with an open configuration can enable imaging of human-size volumes for interventional operations. In this study, we present simulation results for an FFL scanning open MPI system configuration to scan 3D field of view volume electronically. We analyze 3D imaging performance for various SNR levels at a low gradient value of 0.5 T/m that is relevant for clinical-size systems.
磁共振粒子成像（MPI）是一种新兴的模态，可对体内的磁性纳米粒子分布进行成像。该方法基于磁性纳米粒子对施加磁场的非线性响应。在这项研究中，我们提出了使用可电子扫描无场线（FFL）的开磁路 MPI 系统进行三维（3D）层析成像的模拟结果。使用相对较低的 0.5 T/m 梯度场对 26×26×10 mm 体积的视场进行成像。提出了两种 3D 体模的成像结果：字母体模和具有狭窄区域的血管体模。使用基于系统矩阵的重建方法，使用代数重建技术（ART）和交替方向乘子法（ADMM）方法获得图像。在高 SNR 条件下，ADMM 可以清晰地识别狭窄区域。随着噪声水平的增加，低梯度强度的影响变得明显，导致层间耦合伪影。临床相关性-磁共振粒子成像（MPI）是一种具有高时空分辨率的新型示踪剂成像模态。MPI 可以绘制体内引入的超顺磁性氧化铁纳米粒子的定量分布。具有开放式配置的无场线扫描 MPI 系统可实现人体大小体积的介入操作成像。在这项研究中，我们提出了使用 FFL 扫描开放式 MPI 系统配置进行电子扫描 3D 视场体积的模拟结果。我们分析了在与临床系统相关的低梯度值 0.5 T/m 下，各种 SNR 水平的 3D 成像性能。
