[1] Duke Univ, Med Ctr, Dept Radiol, 2301 Erwin Rd,Box 3808, Durham, NC 27710 USA
[2] Duke Univ, Med Ctr, Dept Surg, Durham, NC 27710 USA
[3] Duke Univ, Dept Biostat & Bioinformat, Durham, NC USA
[4] Univ N Carolina, Sch Med, Dept Radiol, Chapel Hill, NC 27515 USA
[5] Univ N Carolina, Dept Epidemiol, Chapel Hill, NC 27515 USA
[6] Univ N Carolina, Lineberger Comprehens Canc Ctr, Chapel Hill, NC 27515 USA