Fig. 3

a T2-weighted MRI of different concentrations of Cy7-SPIONs and peptide/Cy7-SPIONs probes in a 7.0 T magnetic field; b The r1 value of the Cy7-SPIONs probe and two peptide/Cy7-SPIONs probes in a 7.0 T magnetic field; c The r2 value of the Cy7-SPIONs probe and two peptide/Cy7-SPIONs probes in a 7.0 T magnetic field