microvessels embolization imaging ray phase contrast imaging Background: The treatment microcirculatory impairment will have great impact it can be applied to myocardial infarction (M) patients. The problem is how to study these tiny structures and microphenomenon in heart. Methods: We investigated the visualization of cardiac microvessels embolization b the mean of X-ray phase contrast imaging (XPC), which is a recently emerged imaging technique. Using information of X-ray phase shift, it is sensitive to weak absorbing materials. Two SD rats were used as the microvessel embolization samples. MI was surgically induced by ligating left anterior descending artery. Imaging was performed 24 hours post-infarct, with barium sulfate as contrast agent Results: The coronary arteries were visualized with smooth walls and clear edges. The ligated vessels, with the diameter of about three hundred microns, can be clearly distinguished and there were no distal blood flow downstream from these branches The results indicate that phase contrast imaging can directly demonstrate t distribution of microvessels, and estimate the area of MI. The infarct location was in good agreement with pa analyses of the models. Conclusions The advantage of our method is directly observing and evaluating microvessel embolization which simplifies the procedure of diagnoses. Moreover, it is helpful for predicting the prognosis in MI and judging if angiogenesis happens Keywords: X-ray phase contrast imaging (XPCI), Microvessel embolization imaging Myocardial infarction