Parallel MRI using phased array coils

Magnetic resonance imaging (MRI) is a relatively slow imaging technique that has limited its application to imaging of time-varying objects. Developing fast MRI methods has been an active research area for the last three decades. Recently, parallel imaging using phased array coils has provided another avenue to significantly speed up the MRI process. In this article, we describe parallel MRI from a signal processing perspective, invoking the multichannel sampling theory (and filter bank theory). We review several basic reconstruction algorithms and discuss some practical issues and outstanding signal processing problems.