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Updated: Apr 22, 2026

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging
Published on: December 4, 2016
Tuning phenols with Intra-Molecular bond Shifted HYdrogens (IM-SHY) as diaCEST MRI contrast agents
Xing Yang1, Nirbhay N Yadav, Xiaolei Song
1The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 991 N. Broadway Baltimore, MD 21287 (USA).
Abstract:
The optimal exchange properties for chemical exchange saturation transfer (CEST) contrast agents on 3 T clinical scanners were characterized using continuous wave saturation transfer, and it was demonstrated that the exchangeable protons in phenols can be tuned to reach these criteria through proper ring substitution. Systematic modification allows the chemical shift of the exchangeable protons to be positioned between 4.8 to 12 ppm from water and enables adjustment of the proton exchange rate to maximize CEST contrast at these shifts. In particular, 44 hydrogen-bonded phenols are investigated for their potential as CEST MRI contrast agents and the stereoelectronic effects on their CEST properties are summarized. Furthermore, a pair of compounds, 2,5-dihydroxyterephthalic acid and 4,6-dihydroxyisophthalic acid, were identified which produce the highest sensitivity through incorporating two exchangeable protons per ring.
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