Design and analysis of a multiplexing data acquisition system for use in magnetic resonance imaging

Abstract

One of the recent innovations in magnetic resonance imaging (MRI) has been the array coil. It has been shown that using array coils and a fixed set of parameters, one can either decrease imaging time, increase image resolution, or increase image signal-to-noise ratio over normal single channel imaging. However, to gain maximum benefit from the array coil one must acquire images from the individual elements simultaneously. This presents the need for a multiple channel acquisition system. To date, this has been achieved by simply increasing the number of complete receiver channels within the imager system to accommodate the additional receiver coils. This dissertation is based on work that was done to provide an alternative solution to the multi-channel problem. Multiplexing is proposed and implemented as a possible solution for achieving multi-channel capability with as little modification to a normal single channel system as possible. The theory, implementation, and problems involved are discussed in detail and the operation of a multiplexer is demonstrated. Also, as an example, multiplexing technology is used to implement a micro coil array for use in microscopy. Finally, this study draws conclusions as to the usefulness of multiplexing in clinical and research environments and discusses future areas of research that can be pursued in order to enhance the multiplexer's capabilities.