[1] Univ Western Ontario, Western Univ, St Josephs Hlth Care London, Radiol & Oncol,Dept Med Imaging, 268 Grosvenor St, London, ON N6A 4V2, Canada
[2] Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave,Box 29, New York, NY 10065 USA
[3] Univ Arizona, Dept Med Imaging, 1501 North Campbell Ave, Tucson, AZ 85724 USA
[4] Univ Washington, Dept Radiol, 1959 Northeast Pacific St, Seattle, WA 98195 USA
[5] Sutter Med Fdn, 1500 Expo Pkwy, Sacramento, CA 95815 USA
[6] Stanford Univ, Med Ctr, Dept Radiol, 300 Pasteur Dr,H1307, Stanford, CA 94305 USA