Multimodal neuroimaging based classification of autism spectrum disorder using anatomical, neurochemical, and white matter correlates

• Published in: Cortex 2015-05, Vol.66, p.46-59
• Main Authors: Libero, Lauren E., DeRamus, Thomas P., Lahti, Adrienne C., Deshpande, Gopikrishna, Kana, Rajesh K.
• Format: Article
• Language: English
• Subjects: Adult; Anisotropy; Aspartic Acid - analogs & derivatives; Aspartic Acid - metabolism; Autism; Autism Spectrum Disorder - metabolism; Autism Spectrum Disorder - pathology; Autism Spectrum Disorder - physiopathology; Brain - metabolism; Brain - pathology; Brain - physiopathology; Broca Area - metabolism; Broca Area - pathology; Broca Area - physiopathology; Case-Control Studies; Classification; Corpus Callosum - metabolism; Corpus Callosum - pathology; Corpus Callosum - physiopathology; Creatine - metabolism; Diffusion Tensor Imaging; DTI; Female; Functional Neuroimaging; Gyrus Cinguli - metabolism; Gyrus Cinguli - pathology; Gyrus Cinguli - physiopathology; Humans; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; MRI; Multimodal Imaging; Multimodal neuroimaging; Neural Pathways; Organ Size; Parietal Lobe - metabolism; Parietal Lobe - pathology; Parietal Lobe - physiopathology; Prefrontal Cortex - metabolism; Prefrontal Cortex - pathology; Prefrontal Cortex - physiopathology; Spectroscopy; Temporal Lobe - metabolism; Temporal Lobe - pathology; Temporal Lobe - physiopathology; White Matter - metabolism; White Matter - pathology; White Matter - physiopathology; Young Adult
• ISSN: 0010-9452; 1973-8102
• DOI: 10.1016/j.cortex.2015.02.008

Neuroimaging techniques, such as fMRI, structural MRI, diffusion tensor imaging (DTI), and proton magnetic resonance spectroscopy (1H-MRS) have uncovered evidence for widespread functional and anatomical brain abnormalities in autism spectrum disorder (ASD) suggesting it to be a system-wide neural systems disorder. Nevertheless, most previous studies have focused on examining one index of neuropathology through a single neuroimaging modality, and seldom using multiple modalities to examine the same cohort of individuals. The current study aims to bring together multiple brain imaging modalities (structural MRI, DTI, and 1H-MRS) to investigate the neural architecture in the same set of individuals (19 high-functioning adults with ASD and 18 typically developing (TD) peers). Morphometry analysis revealed increased cortical thickness in ASD participants, relative to typical controls, across the left cingulate, left pars opercularis of the inferior frontal gyrus, left inferior temporal cortex, and right precuneus, and reduced cortical thickness in right cuneus and right precentral gyrus. ASD adults also had reduced fractional anisotropy (FA) and increased radial diffusivity (RD) for two clusters on the forceps minor of the corpus callosum, revealed by DTI analyses. 1H-MRS results showed a reduction in the N-acetylaspartate/Creatine ratio in dorsal anterior cingulate cortex (dACC) in ASD participants. A decision tree classification analysis across the three modalities resulted in classification accuracy of 91.9% with FA, RD, and cortical thickness as key predictors. Examining the same cohort of adults with ASD and their TD peers, this study found alterations in cortical thickness, white matter (WM) connectivity, and neurochemical concentration in ASD. These findings underscore the potential for multimodal imaging to better inform on the neural characteristics most relevant to the disorder.