Sequential T1w (top) and CEST (bottom) images of a phantom containing Eu2+2 (1 mL, 10 mM, left) and H2O (right) after the injection of H2O2 (3%, 20 μL). Imaging parameters: B0=9.4 T, 20°C T1w: FSEMS sequence, TR = 2 s, TE = 5 ms; PARACEST: FSEMS sequence, sat time = 3 s, sat power = 10 μT, sat frq = 54 (on-resonance),-54 ppm (off-resonance).