Fast Field-Cycling MRI for molecular dynamics imaging

摘要

Fast Field-Cycling (FFC) MRI is a new noninvasive technology~1 that allows measuring quantitative information on molecular dynamics time scales, from tens of nanoseconds to a few milliseconds, by varying the magnetic field during a pulse sequence to generate T_1-based contrast. In the body T_1 is closely linked to the autocorrelation function of water and fatty molecules so its fielddependant spectrum, also called the T_1 dispersion curve, provides a direct view of molecular motions over a range of time scales that is determined by the strength of the magnetic field, via the Larmor frequency of the spin system observed. The T_1 dispersion curve has been used for decades to study materials and various models exist that predict the dispersion profiles in particular microscopic environments 2-6. Our efforts over the last years have focused on developing a system able to measure T_1 dispersion curves in vivo to exploit this source of information in medicine and to provide unique insights of tissue architectures.