Purpose To investigate the feasibility of apoptosis small-molecule probe CYS-F for in vivo molecular imaging in acute middle cerebral artery embolization and recalculation models,and to explore its ability to reflect lesions.Materials and Methods Hela cell apoptosis was induced by Adriamycin,and the targeting ability of the probe was verified in vitro.Clinical middle cerebral artery embolization was simulated,acute ischemic stroke model(n=15)and recanalization model(n=15)were constructed,and the vessels were evaluated by magnetic resonance angiography imaging.The distribution of CYS-F was investigated by injecting the probe into the caudal vein.24 hours after modeling,the lesion volume rate was assessed on T2WI,and apoptosis was assessed in vivo by near infrared imaging.Niss and c-fos staining were used to compare the differences between the two groups.Results CYS-F showed a good ability to target apoptosis in vitro.After modeling,Doppler flowmeter and magnetic resonance angiography showed that the middle cerebral artery was successfully embolized in the embolization group,and the artery was recanalized in the recanalization group.Near infrared imaging showed the loss of fluorescence signal in the middle cerebral artery region in the embolized group.24 hours after modeling,T2WI showed that the infarct volume rate in the recanalization group was significantly lower than that in the embolization group(0.055±0.015 vs.0.512±0.220;t=19.761,P<0.001).The fluorescence intensity of the embolization group was significantly stronger than that of the recusing group,the target to background ratio was 1.215±0.162 and 0.731±0.085,respectively(t=10.252,P<0.001).In the embolization group,a large number of activated neurons expressed c-fos protein,and a large number of cells underwent nuclear condensation and lysis by Niss staining.Conclusion The acute embolization model and recalculation model of middle cerebral artery in mice are close to the clinic.CYS-F can be used to image apoptosis in vivo,reflect the lesion degree,and reflect the local tissue blood perfusion at the initial stage of injection.