Local System Matrix Compression for Efficient Reconstruction in Magnetic Particle Imaging
Local System Matrix Compression for Efficient Reconstruction in Magnetic Particle Imaging
复制标题
用于磁粒子成像高效重建的局部系统矩阵压缩
DOI：
10.1155/2015/472818
复制
发表时间：
2015
影响因子：
1.2
通讯作者：
A. Weber
中科院分区：
文献类型：
--
作者：
T. Knopp;A. Weber
磁颗粒成像（MPI）是一种确定磁性纳米颗粒空间分布的定量方法，可作为心血管成像的示踪剂。为了重建粒子分布的空间图，描述磁粒子成像方程的系统矩阵必须已知。由于磁性颗粒的复杂动态行为，系统矩阵通常在校准过程中测量。为了加快重构过程，近年来提出了一种利用基变换来压缩MPI系统矩阵的矩阵压缩技术。通过对得到的矩阵进行阈值处理，并以压缩行存储格式存储剩余的条目，在重建粒子分布时只需要处理一小部分数据。在目前的工作中，研究表明，通过对每个矩阵行使用局部阈值而不是对整个系统矩阵使用全局阈值，可以大大提高算法的图像质量。
Magnetic particle imaging (MPI) is a quantitative method for determining the spatial distribution of magnetic nanoparticles, which can be used as tracers for cardiovascular imaging. For reconstructing a spatial map of the particle distribution, the system matrix describing the magnetic particle imaging equation has to be known. Due to the complex dynamic behavior of the magnetic particles, the system matrix is commonly measured in a calibration procedure. In order to speed up the reconstruction process, recently, a matrix compression technique has been proposed that makes use of a basis transformation in order to compress the MPI system matrix. By thresholding the resulting matrix and storing the remaining entries in compressed row storage format, only a fraction of the data has to be processed when reconstructing the particle distribution. In the present work, it is shown that the image quality of the algorithm can be considerably improved by using a local threshold for each matrix row instead of a global threshold for the entire system matrix.