Graphics and Imaging Laboratory, University of Girona, 17071 Girona, Spain.
J Magn Reson Imaging. 2010 Jun;31(6):1435-44. doi: 10.1002/jmri.22178.
To evaluate diffusion anisotropy from diffusion tensor imaging using new measures derived from Hellinger divergences and from compositional data distances.
New anisotropy measures obtained from the diffusion tensor imaging were measured and compared with classic ones such as fractional anisotropy (FA) and relative anisotropy (RA). The evaluation was done using the three-phase plot (3P-plot). The measures were compared with regard to their sensitivity to detect white and gray matter changes on human DTI data acquired from five normal volunteers. For each volunteer, different volumes of interest located in white matter (WM) and gray matter (GM) were considered.
The proposed Compositional Kullback-Leibler (KLA) and the classic FA had a similar behavior, although KLA detected better the transitions between white and gray matter. Moreover, KLA showed a better discrimination in areas with great confluence of fibers.
KLA detects better than FA the difference between WM and GM. This leads KLA to be a good measure for segmenting WM from GM.
利用新的基于 Hellinger 散度和组成数据距离的度量方法，从扩散张量成像中评估扩散各向异性。
使用新的从扩散张量成像中获得的各向异性度量方法，并与经典的各向异性度量方法（如分数各向异性（FA）和相对各向异性（RA））进行比较。使用三相图（3P-plot）进行评估。对这些方法的检测白质和灰质变化的敏感性进行了比较，这些变化是从五名正常志愿者的人体 DTI 数据中获得的。对于每个志愿者，都考虑了位于白质（WM）和灰质（GM）不同感兴趣区域的体积。
提出的组合 Kulback-Leibler（KLA）和经典 FA 具有相似的行为，尽管 KLA 更好地检测到了白质和灰质之间的转变。此外，KLA 在纤维汇聚度较大的区域表现出更好的区分能力。
KLA 比 FA 更能检测 WM 和 GM 之间的差异。这使得 KLA 成为 WM 和 GM 分割的一个很好的度量方法。
