 2. Contraindications for administration of Optison, including but not limited to: Right-to-left cardiovascular shunt, bidirectional cardiovascular shunt, history of myocardial infarction, acute coronary syndrome, pulmonary embolism, pulmonary hypertension, tachycardia, Torsades de Pointes, prolonged Q-T Interval, acute heart failure, vasculitis, emphysema, respiratory compromise, congenital heart disease, hypoxia, allergy to albumin; Individuals objecting to receiving albumin, a blood product, for personal, religious, or cultural reasons. 