Partial/fractional polarization transfer for single-scan magnetic resonance spectroscopy and imaging

摘要

A method of measuring precessing magnetization includes providing a first site characterized by a first spin order and providing a second site. The method also includes transferring a portion of the first spin order from the first site to the second site. The second site is characterized by a second spin order orthogonal to the first spin order. The method further includes exposing a sample including the first site and the second site to a magnetic field, measuring a precessing magnetization of at least one of the first site or the second site, repeating the transferring a portion of the first spin order from the first site to the second site, and repeating the measuring of the precessing magnetization.

主权项

1. A method of measuring precessing magnetization with a magnetic resonance system in a single magnetic resonance scan sequence, the method comprising:
(a) providing, on a first site, a first nucleus having a first spin order; (b) providing, on a second site, a second nucleus; (c) exposing a sample including the first site and the second site to a magnetic field provided by the magnetic resonance system, wherein timing and phase parameters of the magnetic field are determined by a processor in order to achieve a desired transfer efficiency; (d) transferring, as a result of exposing the sample to the magnetic field, a fractional portion of the first spin order of the first nucleus from the first site into a second spin order at the second nucleus on the second site, the transferring occurring at the desired transfer efficiency, and the second spin order being orthogonal to the first spin order; (e) measuring a precessing magnetization of the first site or the second site using a magnetic detector, the measured precessing magnetization indicating either a retained portion of the first spin order or the transferred fractional portion of the first spin order; (f) repeating (c)-(e) a predetermined number of times, with the desired transfer efficiency of each repetition being variable, in order to transfer additional fractional portions of the first spin order from the first site to the second site within the course of the single magnetic resonance scan sequence.