Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL 60616, USA.
IEEE Trans Image Process. 2011 Jan;20(1):176-85. doi: 10.1109/TIP.2010.2059033. Epub 2010 Jul 19.
In image reconstruction gated acquisition is often used in order to deal with blur caused by organ motion in the resulting images. However, this is achieved almost inevitably at the expense of reduced signal-to-noise ratio in the acquired data. In this work, we propose a reconstruction procedure for gated images based upon use of discrete Fourier transform (DFT) basis functions, wherein the temporal activity at each spatial location is regulated by a Fourier representation. The gated images are then reconstructed through determination of the coefficients of the Fourier representation. We demonstrate this approach in the context of single photon emission computed tomography (SPECT) for cardiac imaging, which is often hampered by the increased noise due to gating and other degrading factors. We explore two different reconstruction algorithms, one is a penalized least-square approach and the other is a maximum a posteriori approach. In our experiments, we conducted a quantitative evaluation of the proposed approach using Monte Carlo simulated SPECT imaging. The results demonstrate that use of DFT-basis functions in gated imaging can improve the accuracy of the reconstruction. As a preliminary demonstration, we also tested this approach on a set of clinical acquisition.
在图像重建中，门控采集通常用于处理由于器官运动导致的图像模糊。然而，这几乎不可避免地是以降低采集数据的信噪比为代价的。在这项工作中，我们提出了一种基于离散傅里叶变换（DFT）基函数的门控图像重建方法，其中每个空间位置的时间活动由傅里叶表示来调节。然后通过确定傅里叶表示的系数来重建门控图像。我们在单光子发射计算机断层扫描（SPECT）心脏成像的背景下展示了这种方法，由于门控和其他降级因素，SPECT 成像通常会受到增加的噪声的影响。我们探索了两种不同的重建算法，一种是惩罚最小二乘方法，另一种是最大后验方法。在我们的实验中，我们使用蒙特卡罗模拟 SPECT 成像对所提出的方法进行了定量评估。结果表明，在门控成像中使用 DFT 基函数可以提高重建的准确性。作为初步演示，我们还在一组临床采集上测试了这种方法。
