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Full-Text Articles in Physical Sciences and Mathematics
Controlling Water Exchange Kinetics And Improving Paracest Imaging, Jacqueline R. Slack
Controlling Water Exchange Kinetics And Improving Paracest Imaging, Jacqueline R. Slack
Dissertations and Theses
Generating MR image contrast from exogenous contrast media through chemical exchange saturation transfer (CEST) offers several exciting new possibilities, such as multicolored imaging, the interleaving of pre- and post-contrast images, and the potential to perform ratiometric metabolic imaging. The major limitation of the deployment of CEST imaging is the comparatively high detection limits of exogenous agents and particularly at the low B1 power levels required to meet SAR requirements. The large chemical shifts afforded by paramagnetic (paraCEST) agents permit more rapid exchange kinetics and therefore potentially more effective contrast agents. Despite comparatively large chemical shifts, many Ln3+ DOTA-tetraamide …
Investigations Into The Effects Of Water Exchange And The Structure Of Lanthanide Chelates, Katherine Marie Payne
Investigations Into The Effects Of Water Exchange And The Structure Of Lanthanide Chelates, Katherine Marie Payne
Dissertations and Theses
Lanthanide chelates are effective agents for improving contrast in MR images. Optimizing the relaxation of inner sphere water molecules is a common focus of research in this field. However, the efforts to design an optimal contrast agent have commonly over-looked the relationship of water position and water exchange kinetics. This work explores structural conformation, the impact of very fast water exchange kinetics on hydration, and differing tumbling rates for regioisomers of a number of lanthanide chelates. We have grown crystals of LnDOTMA and obtained structural data by X-ray diffraction that provide a picture of the chelate during water exchange and …