Measurement of Pulmonary Transit Time by Echocardiography: Comparison With Cardiac MRI

The focus of the present study is to further develop an echocardiographic technique to measure cardiopulmonary transit time (PTT) and pulmonary blood volume (PBV) using ultrasound contrast. The Specific Aims for the present study are as follows: 1. To compare echocardiography-based PTTs and cardiac MRI-based PTTs obtained using a 'peak-to-peak' method 2. To further quantify the relationship between echocardiographically-derived PTT, using Optison, and existing echocardiographic methods used to determine ventricular function 3. To measure the reproducibility of echocardiographically-based PTT using Optison.