Schizophrenia Patients Demonstrate Both Inter-Voxel Level and Intra-Voxel Level White Matter Alterations

PLoS One. 2016 Sep 12;11(9):e0162656. doi: 10.1371/journal.pone.0162656. eCollection 2016.

Abstract

Fractional anisotropy (FA) and mean diffusivity (MD) are the most frequently used metrics to investigate white matter impairments in mental disorders. However, these two metrics are derived from intra-voxel analyses and only reflect the diffusion properties solely within the voxel unit. Local diffusion homogeneity (LDH) is a newly developed inter-voxel metric which quantifies the local coherence of water molecule diffusion in a model-free manner. In this study, 94 schizophrenia patients and 91 sex- and age-matched healthy controls underwent diffusion tensor imaging (DTI) examinations. White matter integrity was assessed by FA, MD and LDH. Group differences in these metrics were compared using tract-based spatial statistics (TBSS). Compared with healthy controls, schizophrenia patients exhibited reduced FA and increased MD in the corpus callosum, cingulum, internal capsule, fornix and widespread superficial white matter in the frontal, parietal, occipital and temporal lobes. We also found decreased LDH in the corpus callosum, cingulum, internal capsule and fornix in schizophrenia. Our findings suggest that both intra-voxel and inter-voxel diffusion metrics are able to detect impairments in the anisotropic white matter regions, and intra-voxel diffusion metrics could detect additional impairments in the widespread isotropic white matter regions in schizophrenia.

MeSH terms

  • Adolescent
  • Adult
  • Case-Control Studies
  • Diffusion Tensor Imaging
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Schizophrenia / diagnostic imaging
  • Schizophrenia / pathology*
  • White Matter / pathology*
  • Young Adult

Grants and funding

This study was supported by grants from the National Basic Research Program of China (973 program, 2011CB707801), Natural Science Foundation of China (81501451, 91332113 and 81271551) and Tianjin Key Technology R&D Program (14ZCZDSY00018).