Meyer J H, Gunn R N, Myers R, Grasby P M
MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, DuCane Road, London, W12 0NN, United Kingdom.
Neuroimage. 1999 May;9(5):545-53. doi: 10.1006/nimg.1999.0431.
Recent advances allow robust computation of parametric maps of ligand-receptor binding from PET data sets. Parametric maps may be statistically analyzed at the voxel level, given suitable techniques for both the spatial normalization of image data into a standard space and the application of appropriate statistical tests. The purpose of this study was to spatially normalize parametric maps of [carbonyl-11C]WAY-100635 and [11C]raclopride binding using SPM 96 and ligand-specific templates. Ligand-specific templates were created from integral images taken from healthy subjects. For this, a MRI-based spatial normalization was used: T1-weighted MRI scans were coregistered to the PET integral images, and the spatial normalization of the MRI to the SPM 96 T1 MRI template was applied to the integral images. These integral images were meaned and smoothed to form [carbonyl-11C]WAY-100635 and [11C]raclopride templates. Reliability of spatial normalization using the ligand template method and the previous MRI-based spatial normalization was investigated by using a second set of integral images taken from a different cohort: Landmark coordinates were defined on all spatially normalized integral images. Mean coordinates were found in order to produce an overall (average) landmark for each location. For each image, at each location, the distance from the landmark coordinates to the overall landmark were found. A multivariate analysis of variance was used to examine the effects of observer variance, landmark location, and the method used. Visually acceptable templates were created. While observer variance was not significant, the landmark x method interaction was significant. The ligand template method had significantly smaller distances: Among the landmark locations with this method, the mean distances between individual image landmarks and overall image landmarks ranged from 1. 1 to 4.9 mm. The ligand template method provides a reliable approach for spatial normalization of PET ligand images.
近期的进展使得从正电子发射断层扫描（PET）数据集中稳健地计算配体 - 受体结合的参数图成为可能。给定将图像数据空间归一化到标准空间以及应用适当统计检验的合适技术，参数图可以在体素水平上进行统计分析。本研究的目的是使用SPM 96和配体特异性模板对[羰基 - 11C]WAY - 100635和[11C]雷氯必利结合的参数图进行空间归一化。配体特异性模板是从健康受试者的积分图像创建的。为此，使用了基于磁共振成像（MRI）的空间归一化：将T1加权MRI扫描与PET积分图像进行配准，并将MRI到SPM 96 T1 MRI模板的空间归一化应用于积分图像。这些积分图像进行平均和平滑以形成[羰基 - 11C]WAY - 100635和[11C]雷氯必利模板。通过使用从不同队列获取的第二组积分图像，研究了使用配体模板方法和先前基于MRI的空间归一化进行空间归一化的可靠性：在所有空间归一化的积分图像上定义地标坐标。找到平均坐标以便为每个位置生成一个总体（平均）地标。对于每个图像，在每个位置，找到从地标坐标到总体地标的距离。使用多变量方差分析来检查观察者方差、地标位置和所使用方法的影响。创建了视觉上可接受的模板。虽然观察者方差不显著，但地标×方法的交互作用显著。配体模板方法的距离明显更小：在使用该方法的地标位置中，单个图像地标与总体图像地标之间的平均距离范围为1.1至4.9毫米。配体模板方法为PET配体图像的空间归一化提供了一种可靠的方法。
