Develop of MRI Techniques for Drug-Abuse Applications

头部运动是功能性磁共振成像（fMRI）实验中常见的问题，特别是在涉及药物注射的研究中。提出了一种利用对被试自身头部运动信息的实时反馈进行自主头部运动抑制的方法。为此，在标准磁共振成像硬件上开发了实时功能磁共振成像系统。将头部运动信息反馈简化为一个四向箭头组，当复合在线头部运动指数超过预设阈值时，由绿色变为红色。为了将头部运动信息反馈整合到常用的视觉言语N-BACK任务中，在E-Prime中对箭头指示进行了编程。所有被试的头部运动都得到了明显的抑制，而对任务表现的影响和对大脑活动的干扰已降至最低水平。在我们的fMRI实验中，这种方法已被常规用于质量保证和减少头部运动。

Head motion is a common problem in functional MRI (fMRI) experiments, particularly in studies involving injections of drugs. A voluntary head-motion suppression method using the feedback to subjects on their own head motion information in real time is proposed. A real-time fMRI system was developed on standard MR imaging hardware for this purpose. The feedback of head motion information was simplified as a four-way arrow group changing color from green to red when a composite online head motion index went beyond a pre-specified threshold. The arrow indicators were programmed in E-Prime in order that the feedback of head motion information could be integrated into the commonly used visual verbal N-BACK task. A significant suppression of head motion was obtained consistently on all the subjects while the influence on the performance of task and the interference to brain activation had decreased to a minimal level. This method has been routinely used for quality assurance and reduction of head movement in our fMRI experiments.