Intravenous contrast agents that traverse the pulmonary circulation have been used for endocardial border definition, myocardial perfusion, diagnosis of intracardiac thrombi, and in cardiovascular emergencies such as myocardial rupture. We report a patient who presented with a new inferior myocardial infarction and an extracardiac mass compressing the right atrium, in whom diagnosis of right coronary pseudoaneurysm was made on the basis of delayed appearance of Optison contrast into the pseudoaneurysm and was subsequently confirmed by angiography and surgery. Thus, we extend the diagnostic indication of myocardial contrast agents to patients with extracardiac masses.