Development, simulation, and validation of NMR relaxation-based exchange measurements.
Two-dimensional (2D) nuclear magnetic resonance correlation experiments have recently been proposed as a means for studying exchange in porous media. Most notable of these is the T(2)-T(2) relaxation exchange spectroscopy (REXSY) experiment. Unfortunately, quantifying exchange with this method requires a relatively long, three-dimensional acquisition. To reduce acquisition times, novel 2D methods for quantifying exchange were developed. For each method, model equations were derived (for an arbitrary N-pool system), tested via simulation studies, and validated via experimental studies in an aqueous urea model system. Results indicate that the novel methods outperform REXSY-in terms of uncertainty per unit time for the fitted exchange rate-for certain model systems. The relative merits of each method are discussed in the text.
Dortch
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Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37232-2310, USA.
Horch
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Does
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D007202:Indicators and Reagents / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D011522:Protons; D014508:Urea / Q000737:chemistry; D014867:Water / Q000737:chemistry
D007202:Indicators and Reagents; D011522:Protons; D014867:Water; D014508:Urea