Superior vena cava, right pulmonary artery or both: real time two- and three-dimensional transthoracic contrast echocardiographic identification of the echo-free space posterior to the ascending aorta.

We describe the usefulness of contrast echocardiography and live/real time three-dimensional transthoracic echocardiography in characterizing the normal structures imaged posterior to the proximal ascending aorta as superior vena cava, right pulmonary artery, or both.