Attention deficit/hyperactivity disorder Classification based on deep spatio-temporal features of functional Magnetic Resonance Imaging

Attention deficit/hyperactivity disorder is a neurological disorder characterized by inattention, hyperactivity and impulsivity. Since the resting functional magnetic resonance imaging (rs-fMRI) can reflect the brain activity state, automatic diagnosis of attention deficit/hyperactivity disorder (ADHD) based on re-fMRI has become a critical method which can relieve the pressure of doctors meanwhile improve the efficiency and accuracy of diagnosis. Up to now, the traditional diagnosis of ADHD based on rs-fMRI converts rs-fMRI into functional connectivity or low-dimensional data for classification which will lead to original information loss since rs-fMRI contains 3D spatial and 1D temporal information. In this paper, we propose a deep learning model consisting of the spatio-temporal feature extraction and classifier. The nested residual convolutional denoising autoencoder (NRCDAE) is exploited to reduce the spatial dimension of rs-fMRI and extract the 3D spatial features. Then, the 3D convolutional gated recurrent unit (GRU) is adopted to extract the spatial and temporal features simultaneously. The spatio-temporal features extracted are sent into the sigmoid classifier for classification. The training and testing are carried out across five sites of ADHD-200 and the results of experimental show that the proposed method can effectively improve the classification performance between ADHD and typically developing (TD) in the cross-site test set from 1.14% to 10.9% compared with other methods. To our knowledge, the 3D convolutional GRU is first employed to extract the features of the fMRI and the model has better generalization than other models.