Reinders A A T S, Paans A M J, de Jong B M, den Boer J A, Willemsen A T M
Department of Biological Psychiatry, Groningen University Hospital, 9700 RB Groningen, The Netherlands.
Neuroimage. 2002 Jan;15(1):175-81. doi: 10.1006/nimg.2001.0963.
The significance of task-induced cerebral blood flow responses, assessed using statistical parametric mapping, depends, among other things, on the signal-to-noise ratio (SNR) of these responses. Generally, positron emission tomography sinograms of H(2)(15)O activation studies are reconstructed using filtered backprojection (FBP). Alternatively, the acquired data can be reconstructed using an iterative reconstruction procedure. It has been demonstrated that the application of iterative reconstruction methods improves image SNR as compared with FBP. The aim of this study was to compare FBP with iterative reconstruction, to assess the statistical power of H(2)(15)O-PET activation studies using statistical parametric mapping. For this case study, PET data originating from a bimanual motor task were reconstructed using both FBP and maximum likelihood expectation maximization (ML-EM), an iterative algorithm. Both resulting data sets were statistically analyzed using statistical parametric mapping. It was found, with this dataset, that the statistical analysis of the iteratively reconstructed data confirm the a priori expected physiological response. In addition, increased Z scores were obtained in the iteratively reconstructed data. In particular, for the expected task-related response, activation of the posterior border of the left angular gyrus, the Z score increased from 3.00 to 3.96. Furthermore, the number of statistically significant clusters doubled while their volume increased by more than 50%. In conclusion, iterative reconstruction has the potential to increase the statistical power in H(2)(15)O-PET activation studies as compared with FBP reconstruction.
使用统计参数映射评估的任务诱发脑血流反应的意义，除其他因素外，还取决于这些反应的信噪比（SNR）。一般来说，H(2)(15)O激活研究的正电子发射断层扫描正弦图是使用滤波反投影（FBP）重建的。或者，采集到的数据可以使用迭代重建程序进行重建。已经证明，与FBP相比，应用迭代重建方法可提高图像信噪比。本研究的目的是比较FBP和迭代重建，使用统计参数映射评估H(2)(15)O-PET激活研究的统计功效。对于这个案例研究，使用FBP和最大似然期望最大化（ML-EM，一种迭代算法）对来自双手运动任务的PET数据进行重建。使用统计参数映射对两个所得数据集进行统计分析。在这个数据集中发现，对迭代重建数据的统计分析证实了先验预期的生理反应。此外，在迭代重建数据中获得了更高的Z分数。特别是，对于预期的与任务相关的反应，左侧角回后缘的激活，Z分数从3.00增加到3.96。此外，具有统计学意义的簇数量增加了一倍，而其体积增加了50%以上。总之，与FBP重建相比，迭代重建有可能提高H(2)(15)O-PET激活研究的统计功效。
