RESUMO
Purpose Sustained attention dysfunction is a common symptom of patient with attention-deficit/hyperactivity disorder (ADHD).To reveal the neural mechanism of the abnormality of sustained attention of patients with ADHD,the cerebral blood flow (CBF) abnormalities in patients were studied by perfusion imaging.Materials and Methods Sixteen children with ADHD and twenty normal controls treated at the 401st Hospital of PLA from June 2013 to September 2015 underwent 3D arterial spin labeling (3D-ASL)scanning with GE 3.0T MRI scanner.The participants were performed four continuous sections of sustained attention to response task (SART) for 20 minutes in the scanner.Using SPM 8 toolkit,the local CBF values of both groups were compared in a voxel-wise manner,and their correlations with response time and target accuracy of SART were analyzed.Results When performing the SART,the patients with ADHD showed significantly inhibited trend of increasing CBF in the anterior cortex like dorsal cortex,medial prefrontal cortex,and motor area;however,they presented enhanced trend of increasing CBF in the posterior cortex such as posterior cingulate cortex and parietooccipital sulcus (P＜0.01);the change of CBF in the dorsal prefrontal cortex and that in the precentral and postcentral gyrus had significant correlation with response time of SART task and targeting ratio (dorsal prefrontal cortex:r=0.745,P＜0.001;r=0.591,P＜0.001;r=-0.521,P＜0.001.Precentral and postcentral gyrus:r=0.579,P＜0.001).Conclusion Patients with ADHD show different CBF redistribution between anterior and posterior cerebral cortex in performing SART,and the abnormal CBF shows significant correlations with behavioral metrics,which reflects the mechanism of sustained attention dysfunction of patients with ADHD.