Joshua Friedman1,2, Michael McMahon1,
James Stivers2, Peter Christiaan van Zijl1
1Radiology, Johns Hopkins University
School of Medicine, Baltimore, MD, United States; 2Pharmacology
and Molecular Sciences, Johns Hopkins University School of Medicine,
Baltimore, MD, United States
Currently,
CEST compounds are detected using radiofrequency (RF) based saturation
transfer followed by asymmetry analysis of the magnetization transfer
spectrum. We report an approach that, instead of saturation transfer, employs
a series of so-called label-transfer modules (LTMs), in which frequency
labeling and consecutive transfer of labeled protons to water is achieved. No
asymmetry analysis is needed and exchangeable protons at multiple frequencies
can be detected simultaneously through the water proton signal, while
maintaining specific frequency information of the individual solute protons.
As a first example, the method is applied to a DNA sample and the theory
confirmed experimentally.