A Single-Sided Magnetic Particle Imaging Scanner for In Vivo Breast Cancer Imaging

磁粒子成像(MPI)是一种新兴的非侵入性断层成像方式； CT或MRI，它可以作为一种安全的诊断技术应用于临床和研究环境，但 没有电离辐射或有毒示踪剂。MPI临床面临的主要挑战之一 平移是一种将线圈放大到环绕人体的能力，同时能够 以产生和驱动高空间所需的足够强的磁场梯度 决议。然而，这些要求要求在 具有圆柱形几何图形的设备；因此，替代拓扑，如开放几何图形 扫描仪，将是非常可取的。这项提议的目标是开发一种新颖的单面 MPI成像仪，并在啮齿动物体内演示癌症成像。单面设备具有所有 成像体积一侧的硬件；因此，这样的设备可以同等地使用 用于小动物和人类的多维诊断成像和MPI 光谱仪(MPS)。在我们独特的方法中，我们将开发一种单面MPI成像器 更有前景的场拓扑，即无场线(FFL)，而不是更常见的 并且相对更容易实现无场点(FFP)几何，对于势场 信噪比提高10倍，图像重建更稳健，视场更大。 到目前为止，我们已经建立了第一个具有FFL几何形状的单面线圈组件的原型 它由单边配置的所有所需线圈组成。测量到的磁场 与模拟结果完全一致。我们通过演示来进一步验证我们的设备 使用点源体模进行磁粉信号检测。开发一种完全有能力的 基于单面几何的多维扫描仪在乳腺中的直接临床意义 癌症成像。我们追求两个具体目标：1)开发一种多维成像技术， 它可以在我们的单面设备中实现。这一目标的主要目标是 极大地提高了设备的灵敏度，并识别出结合了 选择线圈和激励线圈，并与我们独特的表面线圈接收器配合工作 接近。我们将实施所需的硬件改造和信号自动化。2) 通过获取MPI图像验证成像方法。MPI扫描仪的性能 将使用带有氧化铁纳米颗粒的模体进行分析。最后，我们将对扫描仪进行验证 荷瘤小鼠的体内成像表现。 拟议研究的总体优势在于开发了有史以来第一台MPI扫描仪 可能会被转化为临床环境。具体地说，我们希望提供一个更敏感的 以及对妇女健康有直接影响的乳腺癌筛查的非侵入性工具。

Magnetic Particle Imaging (MPI) is an emerging non-invasive tomographic imaging modality; like CT or MRI, it could be applied in clinical and research settings as a safe diagnostic technique, but without ionizing radiation or toxic tracers. One of the major MPI challenges toward clinical translation has been the ability to scale up the coils to surround a human body while being able to generate and drive the sufficiently strong magnetic field gradient required for high spatial resolution. These requirements, however, demand prohibitively high power consumption in a device with cylindrical geometry; therefore, alternative topologies, such as an open geometry scanner, would be highly desirable. The goal of this proposal is to develop a novel single-sided MPI imager and demonstrate in vivo cancer imaging in rodents. The single-sided device has all the hardware on one side of the imaging volume; therefore, such a device can be used equally well on small animals and humans for multidimensional diagnostic imaging and as an MPI spectrometer (MPS). In our unique approach, we will develop a single-sided MPI imager with much more promising field topology, namely, field-free line (FFL) as opposed to the more common and relatively easier to implement field-free point (FFP) geometry, for a potential 10-fold increase of SNR, more robust image reconstruction, and larger field of view. To date, we have built a first prototype of a single-sided coils assembly with the FFL geometry that consists of all the required coils in a unilateral configuration. The measured magnetic field showed perfect agreement with the simulations. We further validated our device by demonstrating magnetic particle signal detection using a point-source phantom. Developing a fully capable multidimensional scanner based on single-sided geometry has direct clinical relevance in breast cancer imaging. We pursue two specific aims: 1) Develop a multidimensional imaging technique, which can be implemented in our single-sided device. The main objectives of this aim are to drastically increase the sensitivity of the device and identify an imaging sequence that combines both selection and excitation coils and works in tandem with our unique surface-coil receive approach. We will implement the required hardware modification and signal automation. 2) Validate the imaging method by obtaining the MPI images. The performance of the MPI scanner will be analyzed using phantoms with iron oxide nanoparticles. Finally, we will validate the scanner performance in in vivo imaging of breast tumor-bearing mice. The overall strength of the proposed research lies in developing the first ever MPI scanner that could potentially be translated to clinical settings. Specifically, we hope to deliver a more sensitive and non-invasive tool for breast cancer screening that has a direct impact on women health.