Real-time functional magnetic resonance imaging and its applications

Abstract

Functional magnetic resonance imaging (fMRI) is a noninvasive imaging technique that is able to detect hemodynamic changes associated with neuronal activity in vivo. In the past decade, it has been used extensively for mapping functional neuroanatomy in basic neuroscience and clinical applications. A typical fMRI study includes acquisition of a time series of images (during which the subject is instructed to perform certain tasks) and offline processing and analysis of the image series. In real-time fMRI (rtfMRI), however, image processing and analysis start shortly after the beginning of the scan and then follow the image acquisition procedure as closely as possible. Real-time fMRI provides not only a useful tool for effective quality assurance of fMRI studies, but also opportunities for designing functional examinations with interactive controls and feedback. In this chapter, we describe the basic concept and technical solution of rtfMRI, with a focus on a technique that we have recently developed and implemented on a Siemens 3T MRI scanner. We then demonstrate potential applications of rtfMRI techniques for neurofeedback and motion artifact reduction. In particular, we present a novel method of voluntary head-motion suppression using the feedback of the subject's own motion information in real time. This method was tested and the possible influence on the performance of tasks in fMRI study was assessed utilizing a commonly used working memory task. Our experiments showed that significant suppression of head motion was achieved consistently while the influence on the performance of task and the interference to brain activation could be minimized by careful design of the feedback system. © 2012 by Nova Science Publishers, Inc. All rights reserved.