1. Division of Cardiology, Department of Medicine, University of California, San Francisco (M.A.S.).
2. Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, University of Pittsburgh Medical Center, PA (J.M.C.).
3. Division of Cardiology, Department of Medicine, University of Pittsburgh, PA. (J.M.C.)
4. Department of Bioengineering, University of Pittsburgh, PA. (D.S.K.)