Fig. 3From: A nitroxides-based macromolecular MRI contrast agent with an extraordinary longitudinal relaxivity for tumor imaging via clinical T1WI SE sequence a Temporary concentration changes of nitroxides after injection of Linear pDHPMA-mPEG-Ppa-PROXYL and 3-CP in normal mice for 24Â h. b The concentration changes within 1Â h shown in the inset plotBack to article page