2019年6月14日 · 磁粒子成像（MPI）是基于断层影像技术检测超顺磁性氧化铁纳米颗粒（SPIONs）空间分布的示踪方法。 MPI具有三维成像、高时间分辨率、高空间分辨率和高灵敏度，且无电离辐射危害的优点。 此外，使用的示踪剂不含肾毒性和造成全身系统严重不良反应的物质。 MPI不显示解剖结构，无背景信号干扰，信号强度与示踪剂浓度成比例，是一种可以获得定量数据的检查方法。 这些特性预示着MPI具有医学应用潜力。 笔者对MPI的成像基本原理、成像示 …

MPI系统采用FFP（Field Free Point）轨迹扫描方式，通过精确控制驱动场来实现部分视场（pFOV）和整个视场（wFOV）的覆盖。 成像方法基于幅度调制（AM）技术，通过处理接收到的信号来重建图像。 这一过程涉及到将wFOV分割成多个pFOVs，然后通过控制驱动场来获取所需的切片数量，最后通过AM方法处理信号以重建每个pFOV中的切片。 尽管该系统在磁场梯度和视场方面取得了显著进展，但其空间分辨率和灵敏度仍有提升空间。 此外，系统目前没有封闭循环 …

Magnetic particle imaging (MPI) is a novel imaging method that was first proposed by Gleich and Weizenecker in 2005. Applying static and dynamic magnetic fields, MPI exploits the unique characteristics of superparamagnetic iron oxide nanoparticles ...

2024年10月3日 · By employing a flexible FFP trajectory, the MPI system can achieve an image sampling rate of up to 4 Hz for a 3D Field of View (FoV) of 60 × 40 × 60 mm 3, enabling real-time MPI-based navigation. Furthermore, the proposed navigation control strategy can reach any target outlet within the 3D blood model with a low mean error in vFFP ...

2024年11月18日 · Abstract: In this article, we propose a novel approach of mixing-space magnetic particle imaging (MPI) based on the combination of the spatial domain and frequency domain. For 2-D MPI, the superparamagnetic iron oxide nanoparticles (SPIONs) spectra are measured for frequency-domain reconstruction in the x-direction, whereas the SPION spectra in ...

The imaging experiments were performed on the Berkeley field free line (FFL) projection MPI scanner (Fig. 7(a)) and 3D FFP MPI scanner (Fig. 7(b)). The gradient strength of FFL scanner is 2.25 T/m along x and z axes, yielding an imaging resolution of 3.9 mm in z axis and 7.6 mm in x axis with the contrast agent Resovist [ 27 ].

2022年10月1日 · FFP based selection fields for MPI scanners were designed with permanent magnets, electromagnet coils, and a hybrid system. Spatial homogeneity of the gradient field is critical to prevent image artifacts.

2013年4月1日 · Magnetic Particle Imaging (MPI) is a new tracer imaging modality first presented in 2005. MPI employs iron oxide (SPIO) contrast agents for kidney-safe angiography. SPIOs in MPI generate positive, “bright blood” contrast, with no signal from tissue. MPI already achieves fast, high-contrast angiograms with millimeter-scale resolutions. MPI ...

There are two classes MPI selection fields: Field Free Point (FFP) magnets and Field Free Line (FFL) magnets [1, 2, 3]. A FFL selection field has three distinct benefits over a FFP selection field, namely (a) improved spatial resolution, (b) improved speed, and (c) improved SNR which scales with the number of projections [4].

In vivo distribution of SPIONs can be imaged with the Magnetic Particle Imaging (MPI) method, which uses an inhomogeneous magnetic field with a field free region (FFR). The spatial distribution of the SPIONs are obtained by scanning the FFR inside the field of view (FOV) and sensing SPION related magnetic field disturbance.