Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.
Psychiatry Res. 2011 Aug 30;193(2):65-70. doi: 10.1016/j.pscychresns.2011.01.009.
Voxel-based morphometry (VBM) is a hypothesis-free, whole-brain, voxel-by-voxel analytic method that attempts to compare imaging data between populations. Schizophrenia studies have utilized this method to localize differences in diffusion tensor imaging (DTI) derived fractional anisotropy (FA), a measure of white matter integrity, between patients and healthy controls. The number of publications has grown, although it is unclear how reliable and reproducible this method is, given the subtle white matter abnormalities expected in schizophrenia. Here we analyze and combine results from 23 studies published to date that use VBM to study schizophrenia in order to evaluate the reproducibility of this method in DTI analysis. Coordinates of each region reported in DTI VBM studies published thus far in schizophrenia were plotted onto a Montreal Neurological Institute atlas, and their anatomical locations were recorded. Results indicated that the reductions of FA in patients with schizophrenia were scattered across the brain. Moreover, even the most consistently reported regions were reported independently in less than 35% of the articles studied. Other instances of reduced FA were replicated at an even lower rate. Our findings demonstrate striking inconsistency, with none of the regions reported in much more than a third of the published articles. This poor replication rate suggests that the application of VBM to DTI data may not be the optimal way for finding the subtle microstructural abnormalities suggested in schizophrenia.
体素形态计量学（VBM）是一种无假设的、全脑的、体素对体素的分析方法，旨在比较人群之间的成像数据。精神分裂症研究利用这种方法来定位弥散张量成像（DTI）衍生的各向异性分数（FA）在患者和健康对照之间的差异，FA 是衡量白质完整性的指标。虽然鉴于精神分裂症预期存在细微的白质异常，该方法的可靠性和可重复性尚不清楚，但相关出版物的数量仍在增加。在这里，我们分析并结合了迄今为止 23 项使用 VBM 研究精神分裂症的研究结果，以评估该方法在 DTI 分析中的可重复性。迄今为止在精神分裂症 VBM 研究中报告的每个区域的坐标被绘制到蒙特利尔神经学研究所图谱上，并记录其解剖位置。结果表明，精神分裂症患者的 FA 减少分布在整个大脑中。此外，即使是报告最一致的区域，也只有不到 35%的研究文章独立报告了这些区域。其他 FA 减少的区域复制率甚至更低。我们的研究结果表明存在明显的不一致性，在超过三分之一的已发表文章中，没有一个区域被报道过。这种低复制率表明，将 VBM 应用于 DTI 数据可能不是发现精神分裂症中所提示的细微结构异常的最佳方法。
