Kanaan Richard A A, Kim Jin-Suh, Kaufmann Walter E, Pearlson Godfrey D, Barker Gareth J, McGuire Philip K
Section of Neuroimaging, Institute of Psychiatry, London, United Kingdom.
Biol Psychiatry. 2005 Dec 15;58(12):921-9. doi: 10.1016/j.biopsych.2005.05.015. Epub 2005 Jul 25.
Diffusion tensor imaging (DTI) is a relatively new neuroimaging technique that can be used to examine the microstructure of white matter in vivo. A systematic review of DTI studies in schizophrenia was undertaken to test the hypothesis that DTI can detect white matter differences between schizophrenia patients and normal control subjects.
EMBASE, PubMed, Medline, and PsychInfo were searched online and key journals were searched manually for studies comparing anisotropy (a measure of white matter integrity) between patients and control subjects. Nineteen articles were systematically reviewed.
Though 16 studies found differences, methodological and data differences prevented a meta-analysis. Fourteen studies found reduced anisotropy in patients; two studies found only a loss of normal asymmetry. The region of investigation varied across studies, however, and when the same region (for example, the cingulum) was examined in different studies, as many failed to find a difference as found one. These inconsistencies may be the result of small sample sizes and differences in methodology.
Diffusion tensor imaging has yet to provide consistent findings of white matter abnormalities in schizophrenia. Its potential as a means of examining anatomical connectivity may be realized with the study of larger, more homogenous groups of subjects and with ongoing improvements in image analysis.
扩散张量成像（DTI）是一种相对较新的神经成像技术，可用于在活体中检查白质的微观结构。对精神分裂症患者的DTI研究进行了系统综述，以检验DTI能否检测出精神分裂症患者与正常对照者之间白质差异的假设。
通过在线检索EMBASE、PubMed、Medline和PsychInfo，并手动检索关键期刊，以查找比较患者与对照者之间各向异性（一种衡量白质完整性的指标）的研究。对19篇文章进行了系统综述。
尽管16项研究发现了差异，但方法学和数据差异妨碍了进行荟萃分析。14项研究发现患者的各向异性降低；两项研究仅发现正常不对称性丧失。然而，不同研究的调查区域各不相同，并且当在不同研究中检查相同区域（例如扣带）时，未发现差异的研究与发现差异的研究一样多。这些不一致可能是样本量小和方法学差异的结果。
扩散张量成像尚未提供精神分裂症患者白质异常的一致结果。随着对更大、更同质的受试者群体的研究以及图像分析的不断改进，其作为检查解剖连接性手段的潜力可能会得以实现。
