[1] Univ Washington, Sch Med, Dept Radiol, 1144 Eastlake Ave East,LG 212, Seattle, WA 98109 USA
[2] Univ Washington, Sch Publ Hlth, Dept Hlth Serv, Seattle, WA 98195 USA
[3] Hutchinson Inst Canc Outcomes Res, Seattle, WA USA
[4] Univ Calif Los Angeles, David Geffen Sch Med, Dept Med, Los Angeles, CA 90095 USA