[1] Johns Hopkins Univ, Baltimore, MD USA
[2] Salk Inst Biol Studies, San Diego, CA USA
[3] Johns Hopkins Med, Dept Radiol & Radiol Sci, Dept Oncol, Baltimore, MD USA
[4] Dept Surg, Baltimore, MD USA
[5] Johns Hopkins Univ Sch Med, Diagnost Imaging & Body CT, Baltimore, MD USA
[6] Johns Hopkins Univ Sch Med, Russell H Morgan Dept Radiol & Radiol Sci, 600 N Wolfe St, Baltimore, MD 21287 USA