A T-2ex Mri Dy-Based Contrast Agent For Direct Ph Imaging Using A Ratiometric Approach

pH is a critical parameter that has found unique application in magnetic resonance imaging (MRI) mapping acidity in tissues. This study reports a series of Dy-based MR probes that show innovative T-2ex features, governed by proton catalyzed events. With an increase of pH from 5.5 to 8.0, the r(2ex) relaxivity increased dramatically, while the r(1) relaxivity remained unchanged. The resulting r(2ex)/r(1) allowed for concentration-independent and direct mapping of physiologically relevant pH ranges.