摘要目的通过测量三维超短回波(UTE)MR成像两个回波时间的信号衰减,建立评估容积骨皮质孔隙度的方法。方法本研究经伦理委员会批准并符合HIPAA,所有病人均签署知情同意书。骨皮质孔隙标志物即孔隙度指数定义为超短回波(UTE)序列长回波时间影像强度与短回波时间影像强度的比值,结果采用双指数分析方法进行比较。测量16个 Abstract Objective To establish a method to evaluate volume cortical porosity by measuring the signal attenuation at two echo times in three-dimensional ultrashort echo (UTE) MR imaging. Methods The study was approved by Ethics Committee and conformed to HIPAA. All patients signed informed consent form. The porosity index of cortical bone, the porosity index, is defined as the ratio of the image intensity of the long echo time to the image intensity of the short echo time of the ultrashort echo (UTE) sequence. The results are compared using the double exponential method. Measuring 16