McDonough Chris, Newey David, Tonyushkin Alexey
Physics Department, Oakland University, Rochester, MI 48309 USA.
Physics Department, University of Massachusetts Boston, Boston, MA 02125 USA.
IEEE Trans Magn. 2022 Aug;58(8). doi: 10.1109/tmag.2022.3151710. Epub 2022 Feb 15.
Magnetic Particle Imaging (MPI) is an emerging imaging modality that has a potential of complimenting other imaging modalities in clinical practice. Despite many efforts to scale up MPI hardware to date no MPI systems have been demonstrated to accommodate full body imaging. Previously, we introduced hardware and characterized a prototype of a single-sided MPI scanner, where all coils are confined to a single-side of the device, which provides a subject with unrestricted access to the scanning area although with a limited penetration depth. The major difference in our design from the first reported single-sided scanner is in incorporating a field-free line instead of a field-free point, which generally promises higher sensitivity and more robust image reconstruction. However, as inherent to any single-sided configurations the fields in our device are spatially inhomogeneous making it challenging to apply existing imaging techniques. For our specific geometry we implemented spatial encoding scheme and imaging in time-domain making the image reconstruction fast. In this work we present one dimensional imaging of multiple rods phantoms with a single-sided field-free line MPI scanner. The results demonstrate that our scanner is capable of one dimensional imaging of phantoms with a spatial resolution of at least 7 mm without image processing.
磁粒子成像(MPI)是一种新兴的成像方式,在临床实践中具有补充其他成像方式的潜力。尽管迄今为止人们为扩大MPI硬件规模付出了诸多努力,但尚未有MPI系统被证明能够实现全身成像。此前,我们介绍了一种硬件,并对单面MPI扫描仪的原型进行了表征,该扫描仪的所有线圈都局限于设备的一侧,这使得受试者可以不受限制地进入扫描区域,尽管穿透深度有限。我们的设计与首次报道的单面扫描仪的主要区别在于采用了无场线而非无场点,这通常意味着更高的灵敏度和更稳健的图像重建。然而,与任何单面配置一样,我们设备中的磁场在空间上是不均匀的,这使得应用现有的成像技术具有挑战性。针对我们的特定几何结构,我们实施了空间编码方案并在时域进行成像,从而实现快速的图像重建。在这项工作中,我们展示了使用单面无场线MPI扫描仪对多个棒状模型进行的一维成像。结果表明,我们的扫描仪能够对模型进行一维成像,在不进行图像处理的情况下空间分辨率至少为7毫米。