Parker JM, Weller MW, Feinstein LM, Adams RJ, Main ML, Grayburn PA, Cosgrove DO, Goldberg BA, Darge K, Nihoyannopoulos P, Wilson S, Monaghan M, Piscaglia F, Fowlkes B, Mathias W, Moriyasu F, Chammas MC, Greenbaum L, Feinstein SB. Safety of ultrasound contrast agents in patients with known or suspected cardiac shunts. Am J Cardiol. 2013 Oct 01; 112(7):1039-45.