Fig. 4
Representative T1 mapping imaging of liver a and kidney b of one mouse after injection of Branched pDHPMA-mPEG-Ppa-PROXYL. The liver and kidney were labeled with yellow and red arrow, respectively. The darker blue signals in the liver and kidney suggest sharper enhancement in the MR images. The corresponding T1 values were spatially displayed in the liver c and kidney d after injection of Branched pDHPMA-mPEG-Ppa-PROXYL at different durations. e The 1/T1 values for the liver and kidney were quantitatively analyzed (n = 5, *p < 0.05, compared with pre-injection)