School of Biological Health System Engineering, Arizona State University, Tempe, AZ, USA.
Adv Exp Med Biol. 2022;1380:135-155. doi: 10.1007/978-3-031-03873-0_6.
Current density imaging (CDI) was developed with the aim of determining the three-dimensional distribution of externally applied electric current pathways inside a conductive medium, using measurements of magnetic flux density [Formula: see text] data. While the B field may be measurable using instruments such as a magnetometer, in magnetic resonance current density imaging (MR-CDI), an MRI scanner is used to measure the magnetic flux density data induced by current flow. In MR-CDI, the object must be rotated inside the MRI machine to find all three components of the B-field, as only the component of B parallel to the magnet main magnetic field can be measured. In principle, once the all three components of the B field have been obtained from an MR imaging experiment, the current density distribution [Formula: see text] can be reconstructed from Ampere's law [Formula: see text]. However, the need to rotate the object within the MRI scanner limits the usability of this technique. To overcome this problem, researchers have investigated the current density reconstruction problem using only one component of the magnetic flux density B, where q = x, y, z. In this chapter, we discuss numerical algorithms developed to reconstruct the distribution of J information from the measured B-field.
电流密度成像是为了确定在导电介质内部外部施加电流路径的三维分布而开发的，使用磁场密度 [Formula: see text] 的测量数据。虽然可以使用磁场计等仪器测量 B 场，但在磁共振电流密度成像 (MR-CDI) 中，使用 MRI 扫描仪来测量由电流流动引起的磁通密度数据。在 MR-CDI 中，必须将物体旋转到 MRI 机器内部，以找到 B 场的所有三个分量，因为只能测量与磁铁主磁场平行的 B 分量。原则上，一旦从 MRI 成像实验中获得了 B 场的所有三个分量，就可以根据安培定律 [Formula: see text] 从 B 场重建电流密度分布 [Formula: see text]。然而，需要在 MRI 扫描仪内旋转物体限制了该技术的可用性。为了克服这个问题，研究人员已经研究了仅使用磁通密度 B 的一个分量 [Formula: see text] 来重建电流密度重建问题的方法，其中 q=x,y,z。在本章中，我们讨论了为从测量的 B 场重建 J 信息分布而开发的数值算法。
