Hyperpolarised "3He gas production for magnetic resonance imaging of the human air ways

This thesis describes the experimental techniques, and methods employed in hyperpolarised "3He gas production and magnetic resonance imaging of the human air-ways, using spin-echo sequences and MR tagging techniques. An in-house polariser utilising the metastability optical pumping technique was constructed. The main results of this work are concerned with engineering difficulties involved in compressing HP "3He and a large proportion of this PhD thesis details the design, construction, and performance of an in-house built peristaltic compressor. In preliminary imaging experiments using RARE, high signal to noise projection images of the lungs were acquired using less than 0.5 cm"3 (STP) of purely polarised HP gas. Later, increased HP gas quantities (typically 10 cm"3) were obtained by employing the peristaltic compressor. Consequently we could acquire 10 mm thick slices spanning the entire lung following a single "3He gas bolus administration. Finally, the first results using MR tagging techniques in conjunction with "3He imaging to track gas flow during an inspiratory and expiratory manoeuvre are presented. (author)Available from British Library Document Supply Centre- DSC:DXN058970 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo