Vascular anastomotic stenosis is a common complication that could directly cause hypoperfusion of the allograft and lead to delayed graft function, which however is hardly identified with naked eyes (Fig. ) . Three types of anastomotic stenosis models in orthotopic renal transplantation are established to evaluate the feasibility of DIPT-ICF NPs for rapidly diagnosing abnormal anastomosis of graft vasculatures. DIPT-ICF NPs were intravenously administrated into the rabbit models and then the stenosis of the vascular after anastomosis was evaluated. As shown in Fig. , the control kidney without any stenosis showed bright artery and vein and uniform fluorescence distribution. However, for kidney with complete stenosis of the graft artery, no fluorescence signal could be detected, suggesting the function loss of graft artery. For kidney with partial stenosis of the graft artery, only few blood vessels could be light up by the NIR-II fluorescence due to artery blood vessel dysfunction. It is worthy to note that complete blockage of renal veins could also cause the blood insufficient of graft kidney although not so severe as artery dysfunction. Further quantitative analyses of the fluorescence signal intensity obtained from the reconstructed renal vessels and renal graft confirmed that the abnormal vascular anastomosis was accompanied by poor renal reperfusion (Fig. ; S10). represent the arteries, veins, and blood reperfusion of renal grafts. All NIR-II images were captured with a 980 nm laser at the power density of 60 mW/cm 2 , 1319 nm LP, and an exposure time of 200 ms.