Centre for Molecular Biology and Neuroscience & Institute of Basic Medical Sciences, University of Oslo, Norway.
J Neurosci Methods. 2011 Jul 15;199(1):166-72. doi: 10.1016/j.jneumeth.2011.04.026. Epub 2011 Apr 28.
Anatomical standardization (also called spatial normalization) of positron emission tomography (PET) small animal brain images is required to make statistical comparisons across individuals. Frequently, PET images are co-registered to an individual MR or CT image of the same subject in order to transform the functional images to an anatomical space. In the present work, we evaluate the normalization of synthetic PET (synPET) images to a synthetic PET template. To provide absolute error in terms of pixel misregistration, we created a synthetic PET image from the individual MR image through segmentation of the brain into gray and white matter which produced functional and anatomical images in the same space. When comparing spatial normalization of synPET images to a synPET template with the gold standard (MR images to an MR template), a mean translation error of 0.24mm (±0.20) and a maximal mean rotational error of 0.85° (±0.91) were found. Significant decrease in misregistration error was measured when achieving spatial normalization of functional images to a functional template instead of an anatomical template. This accuracy strengthens the use of standardization methods where individual PET images are registered to a customized PET template in order to statistically assess physiological changes in rat brains.
正电子发射断层扫描（PET）小动物脑图像的解剖标准化（也称为空间标准化）是进行个体间统计比较所必需的。通常，为了将功能图像转换到解剖空间，将 PET 图像与同一主体的个体 MR 或 CT 图像配准。在本工作中，我们评估了将合成 PET（synPET）图像标准化到合成 PET 模板的情况。为了提供像素配准的绝对误差，我们通过将大脑分割为灰质和白质，从个体 MR 图像创建了一个合成 PET 图像，从而在相同的空间中生成了功能和解剖图像。当将 synPET 图像的空间标准化与金标准（MR 图像到 MR 模板）进行比较时，发现平均平移误差为 0.24mm（±0.20），最大平均旋转误差为 0.85°（±0.91）。当将功能图像的空间标准化从到解剖模板改为到功能模板时，测量到的配准误差显著减小。这种准确性加强了使用标准化方法的必要性，即个体 PET 图像注册到定制的 PET 模板，以便在大鼠大脑中统计评估生理变化。
