Correction of partial volume effect in SPECT/PET using anatomical information

为了使用单光子发射计算机断层扫描（SPECT）或正电子发射断层扫描（PET）准确和定量地测量放射性同位素在体内的分布，重要的是准确地校正部分体积效应（PVE）。然而，PVE的校正比体内衰减和/或散射的校正更困难。另一方面，可以使用诸如模糊聚类的分割方法从磁共振成像（MRI）提取身体的解剖信息。然后，如果能够将从MRI提取的解剖学信息作为先验知识引入贝叶斯图像重构方法中，则期望能够校正SPECT或PET中的PVE。因此，本研究的目的是开发一种方法，通过在贝叶斯图像重建方法中引入从MRI中提取的解剖信息来校正SPECT或PET中的PVE。2003年，我们开发了一个软件，该软件将从MRI中提取的解剖信息作为贝叶斯图像重建方法的先验知识。2004年，我们继续开发上述软件，并同时开始使用体模实验和临床数据评估该方法的有效性。我们得到了初步的结果，鼓励的可能性，纠正PVE使用上述方法。总之，这种方法似乎是有用的纠正PVE在SPECT或PET。然而，还需要进一步的研究来确定这种方法的有用性，这些研究目前正在进行中。

To accurately and quantitatively measure the distribution of radioisotope in the body using single photon emission computed tomography (SPECT) or positron emission tomography (PET), it is important to accurately correct for the partial volume effect (PVE). However, the correction of PVE is more difficult than that of attenuation and/or scattering in the body. On the other hand, it is possible to extract the anatomical information of the body from magnetic resonance imaging (MRI) using the segmentation method such as fuzzy clustering. Then, it is expected that if the anatomical information extracted from MRI can be introduced as a prior knowledge in the Bayesian image reconstruction method, it becomes possible to correct for PVE in SPECT or PET. Therefore, the purpose of this study was to develop a method for correcting for PVE in SPECT or PET by introducing the anatomical information extracted from MRI in the Bayesian image reconstruction method.In 2003, we developed a software that introduces the anatomical information extracted from MRI as a prior knowledge in the Bayesian image reconstruction method. In 2004, we continued to develop the above software, and simultaneously started to evaluate the usefulness of this method using phantom experiments and clinical data. We obtained the preliminary results that encouraged the possibility of correcting for PVE using the above method.In conclusion, this method appears to be useful for correcting for PVE in SPECT or PET. However, further studies are necessary to establish the usefulness of this method, and these studies are currently in progress.