Resolution and noise properties of MAP reconstruction for fully 3-D PET
Resolution and noise properties of MAP reconstruction for fully 3-D PET
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DOI：
10.1109/42.870259
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发表时间：
2000-05-01
影响因子：
10.6
通讯作者：
Leahy, RM
中科院分区：
文献类型：
--
作者：
Qi, JY;Leahy, RM
我们推导出近似的解析表达式的局部脉冲响应和协方差的图像重建从全三维（3-D）正电子发射断层扫描（PET）数据使用最大后验概率（MAP）估计。这些表达式明确占空间变化的探测器的响应和灵敏度的3-D断层扫描，所得到的空间变化的脉冲响应和协方差使用3-D傅立叶变换计算。截断的高斯分布是用来占的非负约束的MAP重建中使用的方差的影响。使用Monte Carlo模拟和幻影数据的microPET小动物扫描仪，我们表明，近似提供了合理准确的估计对比度恢复和协方差的MAP重建的先验与二次能量函数。我们还描述了如何可以使用这些分析结果来实现近均匀的对比度恢复整个重建体积。
We derive approximate analytical expressions for the local impulse response and covariance of images reconstructed from fully three-dimensional (3-D) positron emission tomography (PET) data using maximum a posteriori (MAP) estimation. These expressions explicitly account for the spatially variant detector response and sensitivity of a 3-D tomograph, The resulting spatially variant impulse response and covariance are computed using 3-D Fourier transforms. A truncated Gaussian distribution is used to account for the effect on the variance of the nonnegativity constraint used in MAP reconstruction. Using Monte Carlo simulations and phantom data from the microPET small animal scanner, we show that the approximations provide reasonably accurate estimates of contrast recovery and covariance of MAP reconstruction for priors with quadratic energy functions. We also describe how these analytical results can be used to achieve near-uniform contrast recovery throughout the reconstructed volume.