[1] Johns Hopkins Univ Hosp, Div Cardiol, Blalock Cardiol Div 524D, Baltimore, MD 21287 USA
[2] Brigham & Womens Hosp, Dept Med, Noninvas Cardiovasc Imaging Program, Boston, MA 02115 USA
[3] Brigham & Womens Hosp, Dept Radiol, Noninvas Cardiovasc Imaging Program, Boston, MA 02115 USA
[4] Brigham & Womens Hosp, Dept Med, Div Cardiovasc Med, Boston, MA 02115 USA
[5] Johns Hopkins Sch Med, Dept Med, Baltimore, MD USA
[6] Johns Hopkins Sch Med, Dept Radiol, Baltimore, MD USA