Theoretical model of the single spin-echo relaxation time for spherical magnetic perturbers.

摘要: Purpose Magnetically labeled cells and tissue iron deposits provide qualitative means to detect monitor cardiovascular cerebrovascular diseases with magnetic resonance imaging. However, quantitatively examine the extent of pathological micromorphological changes, detailed knowledge about microstructural parameters relaxation times is required. Methods The complex geometrical arrangement spherical perturbers considered in an external field. They create a dipole field, whose corresponding spin-echo formation investigated by analyzing diffusion process dephasing volume. Quantitative predictions present analysis are compared experimental data empirical models. Results Single can be characterized morphological such as particle concentration size well coefficient local susceptibility properties. As expected, no static plateau observed contrast gradient-echo time. Instead, rate drops for large sizes exhibits prominent maximal value at intermediate sizes. These findings agree previous theoretical results. Conclusion Obtained results single time allow accurately quantify processes neurodegenerative disease migration dynamics magnetically help Magn Reson Med 71:1888–1895, 2014. © 2014 Wiley Periodicals, Inc.