Kim H J, Zeeberg B R, Loew M H, Reba R C
Department of Radiology, George Washington University, Washington, DC.
J Nucl Med. 1991 Feb;32(2):333-8.
We have applied an efficient algorithm for mathematically simulating the three-dimensional (3-D) response of a SPECT imaging system with a depth-dependent 3-D point spread function (3-DPSF). The input object whose reconstructed image is to be simulated is restricted to a binary map; more complex objects may be treated as linear combinations of binary maps. The 3-D convolution reduces to a sequence of additions of a 3-D line spread function (3-DLSF), appropriately translated, to the 3-D response. We have simulated the projection data from a multidetector SPECT system with point-focusing collimators. The simulated projection data were then reconstructed using the manufacturer's software. The objects simulated included simple geometrical solids such as spheres and cylinders, as well as the distribution of muscarinic cholinergic receptors in a realistic brain slice. The results of these simulations indicate the existence of significant qualitative and quantitative artifacts in reconstructed human brain images.
我们应用了一种高效算法，用于对具有深度依赖三维点扩散函数（3-DPSF）的单光子发射计算机断层扫描（SPECT）成像系统的三维（3-D）响应进行数学模拟。待模拟重建图像的输入对象限于二值图；更复杂的对象可视为二值图的线性组合。三维卷积简化为将经过适当平移的三维线扩散函数（3-DLSF）依次加到三维响应上。我们模拟了带有点聚焦准直器的多探测器SPECT系统的投影数据。然后使用制造商的软件对模拟的投影数据进行重建。模拟的对象包括球体和圆柱体等简单几何实体，以及真实脑切片中毒蕈碱型胆碱能受体的分布。这些模拟结果表明，重建的人脑图像中存在显著的定性和定量伪影。
