NOVEL ENCODING TECHNOLOGY FOR ULTRAFAST MRI

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The aims of the research proposed herein are 1) to design and build a new type of magnetic field encoding coil system to be used in a Magnetic Resonance Imager and 2) to implement and test two applications of this coil system. The two applications are 1) an ultrafast imaging method and 2) extremely efficient quantitative flow imaging techniques, both of which are enabled by the articular geometry of the encoding coils. Using a radically different field geometry, new mathematical algorithms for imaging static and flowing spins are suggested. The research proposed herein is to complete the design of the coil system and then build a prototype. The rapid imaging application will be tested and refined using computer simulations and then tested experimentally. The flow imaging methods will be further developed and tested experimentally with a variety of flow phantoms where the velocity distribution is known a priori. The proposed ultrafast static imaging technique offers the opportunity for imaging without having to switch the current in the encoding coil. Hence, this technique is theoretically faster than those available today (i.e. echo-planar). In addition, because actively shielded gradient coils are not required for this method, the costs of implementing such a method are likely to be substantially less than for echo planar. The availability of low cost real-time imaging could substantially influence the availability of rapid imaging to the medical community. The proposed flow imaging methods offer the opportunity to obtain quantitative velocity information in a single excitation of the nuclei, thus also making this method extremely time efficient. The availability of a fast, accurate and quantitative velocity measuring MRI method would bring new diagnostic capabilities to this noninvasive technique.