Ota Miho, Sato Noriko, Maikusa Norihide, Sone Daichi, Matsuda Hiroshi, Kunugi Hiroshi
Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.
Department of Radiology, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.
Jpn J Radiol. 2017 Oct;35(10):584-589. doi: 10.1007/s11604-017-0670-7. Epub 2017 Jul 26.
The new diffusional magnetic resonance imaging (dMRI) techniques, diffusional kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) have been developed to clarify the microstructural changes. To our knowledge, however, there is little information on the similarities and differences of these metrics evaluated by the image-by-image paired t test.
Twenty-three healthy subjects underwent dMRI. We estimated the relationships of these metrics evaluated by the image-by-image paired t-test and compared aging effects on each metric.
We found that fractional anisotropy (FA), mean kurtosis (MK) derived from DKI and neurite density index (NDI) values derived from NODDI correlated with each other positively, and mean diffusivity (MD) and orientation dispersion index (ODI) values from NODDI correlated negatively with the FA value. There were no significant relationships of age with FA or MD values, while MK, ODI and NDI values showed significant correlations with age.
These results may indicate not only the similar tendency among the metrics, but also the higher sensitivity of NODDI and DKI to the changes in microstructural tissue organization with advancing age. These techniques could shed light on both normal and degenerated brain changes.
新的扩散磁共振成像（dMRI）技术，即扩散峰度成像（DKI）和神经突方向离散度与密度成像（NODDI）已被研发出来以阐明微观结构变化。然而，据我们所知，关于通过逐图像配对t检验评估的这些指标的异同的信息很少。
23名健康受试者接受了dMRI检查。我们估计了通过逐图像配对t检验评估的这些指标之间的关系，并比较了年龄对每个指标的影响。
我们发现，分数各向异性（FA）、DKI得出的平均峰度（MK）以及NODDI得出的神经突密度指数（NDI）值彼此呈正相关，而NODDI的平均扩散率（MD）和方向离散度指数（ODI）值与FA值呈负相关。年龄与FA或MD值之间无显著关系，而MK、ODI和NDI值与年龄呈显著相关。
这些结果可能不仅表明了这些指标之间的相似趋势，还表明了NODDI和DKI对随着年龄增长微观结构组织变化的更高敏感性。这些技术可以揭示正常和退化的大脑变化。
