[1] Univ Michigan, Sch Med, Ann Arbor, MI 48109 USA
[2] Michigan Med, Dept Radiol, Ann Arbor, MI USA
[3] Univ Michigan, Michigan Inst Clin & Hlth Res, Ann Arbor, MI 48109 USA
[4] Univ Calif Irvine, Dept Stat, Irvine, CA USA
[5] Michigan Med, Dept Cardiac Surg, Ann Arbor, MI USA