CEUS imaging of blood circulation in tumors of mice treated with peptide-coated nanoworms. (A) Mice preinjected with Ni-liposomes were subsequently injected with a mixture of CREKA-NWs and CRKDKC-NWs and, after the indicated periods of time, injected with an ultrasound contrast agent. CEUS and conventional ultrasound (US) images obtained at the different time points are shown. The images are representative of 3 tumors imaged. (B) Enhancement-analysis curves of blood flow in different tumor regions and the surrounding tissue from experiments described in panel A. The orientation of the tumors is slightly different between the time points because the mice were anesthetized for each scan and reintroduced to the ultrasound instrument; n = 3.