双平板多功能核医学成像系统几何校正方法研究

双平板多功能核医学成像系统是一套既能够进行正电子发射断层扫描成像(PET)又可以进行单光子发射成像(γ相机)的"一机多用"设备。该系统采用平行双平板结构,通过可移动式准直器组合实现PET模式和γ相机模式的切换。鉴于这一工作模式需求,同时考虑到设备装配过程中的机械精度等因素,系统的几何结构参数校准及与成像过程配套的几何校正变得尤为重要。本文基于双平板多功能核医学成像系统,研究系统几何偏移对图像质量的影响,并对这些误差因素进行参数化表征,建立一套几何参数校正方法。基于蒙特卡洛模拟数据的验证表明,该方法有效可行,流程简洁。 

Geometric Correction Method for Double-plane"Multi-use" Nuclear Medical Imaging System

Double-plane multi-function nuclear medical imaging system can support both Positron Emission Tomography Imaging (PET) and Single Photon Emission Imaging (Gamma camera). It is a "multi-use" device which can switch operating mode between double plane PET andγcamera usingtractablecollimators. Considering the requirements of this special operating mode and the accuracy of the mechanical assembly, it is particularly important to process a series of geometric calibration before data acquisition. After that the calibration factors can be used in data correction or image reconstruction. In this paper, we studied the influence of system geometry offset on image quality and established a set of calibration and correction methods based on the parametricrepresentation of these factors. The performance of correction accuracy was evaluated based on the Monte Carlo simulation data. The results showed that the method is effective, feasible and simple.