Department of Electronic Engineering, Paichai University, Daejeon, Korea.
IEEE Trans Image Process. 2013 Oct;22(10):3961-73. doi: 10.1109/TIP.2013.2265881. Epub 2013 Jun 3.
With the introduction of combined positron emission tomography (PET)/computed tomography (CT) or PET/magnetic resonance imaging (MRI) scanners, there is an increasing emphasis on reconstructing PET images with the aid of the anatomical side information obtained from X-ray CT or MRI scanners. In this paper, we propose a new approach to incorporating prior anatomical information into PET reconstruction using the nonlocal regularization method. The nonlocal regularizer developed for this application is designed to selectively consider the anatomical information only when it is reliable. As our proposed nonlocal regularization method does not directly use anatomical edges or boundaries which are often used in conventional methods, it is not only free from additional processes to extract anatomical boundaries or segmented regions, but also more robust to the signal mismatch problem that is caused by the indirect relationship between the PET image and the anatomical image. We perform simulations with digital phantoms. According to our experimental results, compared to the conventional method based on the traditional local regularization method, our nonlocal regularization method performs well even with the imperfect prior anatomical information or in the presence of signal mismatch between the PET image and the anatomical image.
随着正电子发射断层扫描（PET）/计算机断层扫描（CT）或 PET/磁共振成像（MRI）扫描仪的引入，越来越强调借助从 X 射线 CT 或 MRI 扫描仪获得的解剖学侧信息来重建 PET 图像。在本文中，我们提出了一种利用非局部正则化方法将先验解剖学信息纳入 PET 重建的新方法。为该应用开发的非局部正则化器旨在仅在可靠时选择性地考虑解剖学信息。由于我们提出的非局部正则化方法不直接使用通常用于传统方法的解剖学边缘或边界，因此它不仅不受提取解剖学边界或分割区域的附加过程的影响，而且对由于 PET 图像和解剖学图像之间的间接关系引起的信号不匹配问题也更稳健。我们使用数字体模进行了模拟。根据我们的实验结果，与基于传统局部正则化方法的传统方法相比，即使在不完善的先验解剖学信息或 PET 图像和解剖学图像之间存在信号不匹配的情况下，我们的非局部正则化方法也能很好地工作。
