Rorschach, Harold E., Jr.2009-06-042009-06-041992Minard, Kevin R.. "The effects of stochastic fluid transport phenomena in magnetic resonance imaging (MRI)." (1992) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/13670">https://hdl.handle.net/1911/13670</a>.https://hdl.handle.net/1911/13670Kubo's generalized cumulant expansion theorem is used to derive a theoretical expression for the nuclear magnetic resonance (NMR) signal received from a fluid moving in a time-dependent magnetic field gradient. Described in general terms by time-dependent correlation functions, this expression is used to investigate a new statistical model of microcirculation that incorporates both coherent and incoherent flow effects at the microscopic level. Based on a simple picture of the intravoxel environment, this model is developed by considering an arbitrary distribution of tortuous capillary flows. A statistical analysis of the Langevin equation describing slow tortuous capillary flow as a stochastic process reveals precisely how both coherent and incoherent flow effects contribute to the overall attenuation of the NMR spin-echo. Velocity compensated and non-compensated diffusion matched spin-echo imaging sequences are utilized to separate and quantify these respective effects noninvasively on phantoms of stationary and flowing fluid.158 p.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.BiophysicsBiomedical engineeringPlasma physicsThesisThesis Phys. 1992 Minard