[1] Stanford Univ, Sch Med, Dept Radiol, Stanford, CA 94305 USA
[2] Stanford Univ, Sch Med, Dept Med, Div Cardiol, Stanford, CA 94305 USA
[3] Stanford Univ, Sch Med, Dept Bioengn, Stanford, CA 94305 USA
[4] Stanford Univ, Sch Med, Dept Dev Biol, Stanford, CA 94305 USA
[5] Stanford Univ, Sch Med, Dept Cardiothorac Surg, Stanford, CA 94305 USA
[6] Univ Calif Davis, Dept Cell Biol & Human Anat, Stem Cell Program, Davis, CA USA