Fast chemical shift imaging by the echo planar imaging technique.

Phase-Encoded Pi Echo Planar Imaging (PEPI) may be used for the high-speed acquisition of spatial and spectroscopic data in samples where a distribution of chemically shifted sites is present. A pulse sequence has been developed using SMIS Limited MR3040 hardware and the Pulse Programming Language. In this thesis Chapter One describes the origins and principles of Nuclear Magnetic Resonance (NMR) experiments. Chapter Two describes the application of magnetic field gradients to produce images using pulse Fourier transform NMR. In Chapter Three the development of fast spectroscopic Echo Planar sequences is discussed, leading to a description of the PEPI sequence in Chapter Four. Included is a description of the special instrumentation needed to implement very fast spectroscopic imaging sequences and an analysis of some initial results which addresses issues particularly associated with these techniques. Some examples of applications to 1H studies of the human brain, where spectroscopic EPI presents a special advantage in terms of temporal resolution, and recommendations for future work are given in Chapter Five