Patent ID: 9140769
Filing Date: 2015-09-22
Classification: G01R

Abstract:
1. A method for magnetic resonance (MR) imaging or spectroscopy, comprising: (a) selectively exciting exchangeable solute protons or protons of exchangeable solute-based water molecules within a frequency range in a subject using at least one frequency-selective radio frequency (RF) pulse, wherein said frequency range encompasses characteristic resonance frequencies of the exchangeable solute protons or protons of exchangeable solute-based water molecules, wherein said frequency range is substantially non-overlapping with a characteristic resonance frequency of bulk water protons in said subject, wherein said at least one frequency selective RF pulse performs a substantially minimal excitation on said bulk water protons, and wherein said at least one frequency-selective RF pulse, in combination with a time period that separates said at least one frequency-selective RF pulse, magnetically labels said exchangeable solute protons or said exchangeable solute-based water molecules; (b) allowing a portion of the magnetically labeled exchangeable solute protons to exchange with said bulk water protons or allowing the magnetically labeled exchangeable solute-based water molecules to exchange with bulk water molecules; (c) repeating (a) and (b) a plurality of times to enhance a population size of the magnetically labeled exchangeable solute protons or the magnetically labeled exchangeable solute-based water molecules; (d) irradiating said subject under observation with a water excitation RF pulse that is adapted to excite said hulk water protons; (e) recording a magnetic resonance (MR) signal from said subject under observation in response to said water excitation RF pulse; and (f) analyzing the recorded MR signal to estimate a quantity associated with said exchangeable solute protons or said exchangeable solute-based water molecules.