Fig. 4
pH ultrasensitive high-field T1–T2 dual model MRI contrast. Plotting 1/T1 (a) or 1/T2 (b) versus different concentrations of R-PtMn-1 in HEPES buffer with different pH conditions (2 ×, pH = 7.4, 6.8, 6.4, 5.4, 4.4). c T1- or T2-MRI (7 T) images for different concentrations of R-PtMn-1 in HEPES buffer with different pH conditions (2 ×, pH = 7.4, 6.8, 6.4, 5.4, 4.4). d T1-MRI or T2-MRI images for 4T1 tumor bearing mice at various times, after the local injection of Nr-PtMn-1 or R-PtMn-1 into the tumor. e–f Quantification of T1-MRI or T2-MRI signal intensity of tumor areas from (d). g T1-MRI or T2-MRI images of mice at various times, after i.v. injection of R-PtMn-1. h Quantification of T1-MRI or T2-MRI signal intensity of tumor areas from (g). The statistical analysis was performed in contrast to the control group (*p < 0.05, t-test)