Division of Medical and Biological Informatics, German Cancer Research Center, Heidelberg, Germany.
Psychiatry Res. 2012 Aug-Sep;203(2-3):184-93. doi: 10.1016/j.pscychresns.2011.12.003. Epub 2012 Sep 1.
Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique that provides information on the fiber architecture of the brain by measuring water diffusion. Prior work has shown that neuronal degeneration in Alzheimer's disease (AD) and mild cognitive impairment (MCI) alters this architecture. Since the conversion rate to AD is much higher for MCI patients than for normal healthy people, it is important to identify biomarkers with a predictive value on this conversion. In this study, we applied tract-based spatial statistics (TBSS) on datasets of 15 healthy controls, 15 AD patients, and 17 MCI patients. Of these MCI patients eight remained stable, whereas nine developed AD within the first 12-18 months of follow-up investigations. Analysis using TBSS combined with a maximum likelihood regression with random effects of the fornix, the corpus callosum, and the cingulum identified significant differences between these two types of MCI patients in fractional anisotropy (FA) and radial diffusivity (DR). Thus, DTI reveals Alzheimer-specific changes in those MCI subjects that later convert, although they were clinically identical to the other MCI-patients at the time the data were acquired. This finding could lead to early identification of AD and thereby aid early clinical intervention.
弥散张量成像（DTI）是一种磁共振成像（MRI）技术，通过测量水的扩散来提供大脑纤维结构的信息。先前的研究表明，阿尔茨海默病（AD）和轻度认知障碍（MCI）中的神经元变性改变了这种结构。由于 MCI 患者向 AD 的转化率比正常健康人高得多，因此识别具有这种转化预测价值的生物标志物非常重要。在这项研究中，我们在 15 名健康对照组、15 名 AD 患者和 17 名 MCI 患者的数据集上应用了基于束的空间统计学（TBSS）。在这些 MCI 患者中，有 8 人保持稳定，而有 9 人在 12-18 个月的随访调查中发展为 AD。使用 TBSS 结合纤维束、胼胝体和扣带回的最大似然回归分析随机效应，发现这两种 MCI 患者在各向异性分数（FA）和径向弥散度（DR）方面存在显著差异。因此，DTI 揭示了那些后来转化为 AD 的 MCI 患者的阿尔茨海默病特异性变化，尽管在数据采集时他们在临床上与其他 MCI 患者相同。这一发现可能导致 AD 的早期识别，从而有助于早期临床干预。
