Morbelli S, Rodriguez G, Mignone A, Altrinetti V, Brugnolo A, Piccardo A, Pupi A, Koulibaly P M, Nobili F
Nuclear Medicine Unit , S. Martino University, Hospital, Genoa, Italy.
Q J Nucl Med Mol Imaging. 2008 Mar;52(1):89-98. Epub 2007 Nov 28.
Statistical parametric mapping (SPM) is used worldwide to compare brain perfusion single photon emission computed tomography (SPECT) data. The default template within the SPM package used for SPECT image normalization includes images of a group of healthy subjects studied with [(99m)Tc]HMPAO. Since [(99m)Tc]HMPAO and [(99m)Tc]ECD have shown to distribute differently in SPECT studies, we formulated the hypothesis that comparing set of [(99m)Tc]ECD data normalized by means of a [(99m)Tc]HMPAO template may lead to incorrect results.
A customized [(99m)Tc]ECD template was built with SPECT and magnetic resonance imaging (MRI) images of 22 neurologically healthy women. Then, two sets of subjects, i.e. a group of patients with very early Alzheimer's disease (eAD) and a matched control group, studied by means of [(99m)Tc]ECD SPECT, were chosen for comparisons. The same statistical approach (t-test between eAD patients and controls and correlation analysis between brain SPECT and a cognitive score) was applied twice, i.e. after normalization with either the default [(99m)Tc]HMPAO template or the customized [(99m)Tc]ECD template.
In the comparison between eAD and controls, a cluster of difference in the posterior cingulate gyrus of both hemispheres was only highlighted when using the customized [(99m)Tc]ECD template, but was missed when using the default [(99m)Tc]HMPAO template. In the correlation between brain perfusion and a cognitive score, the significant cluster was more significant and far more extended, also including the right superior temporal gyrus, using the customized [(99m)Tc]ECD template than using the default [(99m)Tc]HMPAO template.
These data suggest the need of customized, radiopharmaceutical-matched SPECT templates to be used within the SPM package. The present customized [(99m)Tc]ECD template is now freely available on the web.
统计参数映射（SPM）在全球范围内用于比较脑灌注单光子发射计算机断层扫描（SPECT）数据。SPM软件包中用于SPECT图像归一化的默认模板包括一组使用[（99m）Tc]HMPAO研究的健康受试者的图像。由于[（99m）Tc]HMPAO和[（99m）Tc]ECD在SPECT研究中显示出不同的分布，我们提出假设，即通过[（99m）Tc]HMPAO模板对[（99m）Tc]ECD数据集进行归一化比较可能会导致错误结果。
利用22名神经功能正常女性的SPECT和磁共振成像（MRI）图像构建了定制的[（99m）Tc]ECD模板。然后，选择两组受试者，即一组极早期阿尔茨海默病（eAD）患者和一个匹配的对照组，通过[（99m）Tc]ECD SPECT进行研究，以进行比较。相同的统计方法（eAD患者与对照组之间的t检验以及脑SPECT与认知评分之间的相关性分析）应用了两次，即在使用默认的[（99m）Tc]HMPAO模板或定制的[（99m）Tc]ECD模板进行归一化之后。
在eAD与对照组的比较中，仅在使用定制的[（99m）Tc]ECD模板时，双侧后扣带回中的一个差异簇才被突出显示，而使用默认的[（99m）Tc]HMPAO模板时则未被发现。在脑灌注与认知评分的相关性方面，与使用默认的[（99m）Tc]HMPAO模板相比，使用定制的[（99m）Tc]ECD模板时，显著簇更显著且范围更广，还包括右侧颞上回。
这些数据表明需要在SPM软件包中使用定制的、与放射性药物匹配的SPECT模板。目前定制的[（99m）Tc]ECD模板现已在网上免费提供。
