Echo-Planar Magnetic Resonance Imaging of Human Brain Activation

Abstract

Development of new methods to image the thinking human brain is fundamental to unraveling the principles of its workings. The latest and most promising functional brain activation imaging techniques to emerge have been those which use magnetic resonance imaging (MRI). The array of MRI-based techniques used for the study of brain activation has been termed functional MRI (fMRI). Echo-planar imaging (EPI), an ultrafast MRI technique [1–5], has been and continues to be ubiquitous in the ongoing development and application of fMRI in general. In the growing number of centers that have EPI capability, it is the fMRI method of choice. An overview of EPI in the study of human brain function is given in this chapter. A brief overview of fMRI is first given. Second, details regarding the implementation of EPI for fMRI, as of May, 1995, are described. Lastly, EPI is discussed in the context of four developing areas in fMRI: imaging platform or methodology development, contrast mechanism research, postprocessing development, and applications. In the areas of imaging platform development and contrast mechanism research, several examples demonstrating the utility of EPI are given.