%0 Journal Article %T AIUM practice guideline for the performance of an ultrasound examination of the extracranial cerebrovascular system. %A %A %A %J J Ultrasound Med %V 31 %N 1 %D Jan 2012 %M 22215783 %F 2.754 %R 10.7863/jum.2012.31.1.145 %X