Neurite orientation dispersion and density imaging reveals white matter microstructural alterations in adults with autism

Molecular Autism

Eiji Kirino¹  Shigeki Aoki²  Christina Andica²  Wataru Uchida²  Ryusuke Irie²  Koji Kamagata²  Syo Murata³ 

[1] Department of Psychiatry, Juntendo University Graduate School of Medicine, Tokyo, Japan;Department of Psychiatry, Juntendo University Shizuoka Hospital, Shizuoka, Japan;Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan;Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan;Department of Radiological Sciences, Faculty of Healthy Sciences, Komazawa University, Tokyo, Japan;

关键词: Autism;    Diffusion tensor imaging;    Linear discriminant analysis;    Neuronal loss;    Neuroinflammation;    Neurite orientation dispersion and density imaging;    Region-of-interest;    Tract-based spatial statistics;    White matter microstructure;   

DOI  :  10.1186/s13229-021-00456-4

来源: Springer

【 摘 要 】

BackgroundEvidences suggesting the association between behavioral anomalies in autism and white matter (WM) microstructural alterations are increasing. Diffusion tensor imaging (DTI) is widely used to infer tissue microstructure. However, due to its lack of specificity, the underlying pathology of reported differences in DTI measures in autism remains poorly understood. Herein, we applied neurite orientation dispersion and density imaging (NODDI) to quantify and define more specific causes of WM microstructural changes associated with autism in adults.MethodsNODDI (neurite density index [NDI], orientation dispersion index, and isotropic volume fraction [ISOVF]) and DTI (fractional anisotropy [FA], mean diffusivity [MD], axial diffusivity, and radial diffusivity [RD]) measures were compared between autism (N = 26; 19 males and 7 females; 32.93 ± 9.24 years old) and age- and sex-matched typically developing (TD; N = 25; 17 males and 8 females; 34.43 ± 9.02 years old) groups using tract-based spatial statistics and region-of-interest analyses. Linear discriminant analysis using leave-one-out cross-validation (LDA-LOOCV) was also performed to assess the discriminative power of diffusion measures in autism and TD.ResultsSignificantly lower NDI and higher ISOVF, suggestive of decreased neurite density and increased extracellular free-water, respectively, were demonstrated in the autism group compared with the TD group, mainly in commissural and long-range association tracts, but with distinct predominant sides. Consistent with previous reports, the autism group showed lower FA and higher MD and RD when compared with TD group. Notably, LDA-LOOCV suggests that NDI and ISOVF have relatively higher accuracy (82%) and specificity (NDI, 84%; ISOVF, 88%) compared with that of FA, MD, and RD (accuracy, 67–73%; specificity, 68–80%).LimitationsThe absence of histopathological confirmation limit the interpretation of our findings.ConclusionsOur results suggest that NODDI measures might be useful as imaging biomarkers to diagnose autism in adults and assess its behavioral characteristics. Furthermore, NODDI allows interpretation of previous findings on changes in WM diffusion tensor metrics in individuals with autism.

【 授权许可】

CC BY