Ultrafast Scanning of Exchangeable Sites by NMR Spectroscopy

摘要

Chemical exchange saturation transfer (CEST) and magnetization transfer (MT) have become widely popular techniques for generating enhanced MRI contrast in vivo and ex vivo. To fully characterize these phenomena and to investigate suitable candidates for contrast agents, the polarization of the reporter signal (typically water) is measured as a function of the frequency offset of the saturating radio-frequency (RF) irradiation (Z-spectrum). Here, we present an ultrafast method to obtain a Z-spectrum over a large range of frequency offsets from only two signal excitations. This method can be useful for fast screening of imaging phantoms and para- and diamagnetic chemical exchange saturation transfer (CEST) contrast agents under different experimental conditions (e.g. saturation time and power).