[1] Kaiser Permanente Los Angeles Med Ctr, Dept Radiol, Los Angeles, CA 90027 USA
[2] Virginia Commonwealth Univ, Med Ctr, Dept Radiol, Richmond, VA USA
[3] Univ Calif San Francisco, Dept Radiol & Biomed Imaging, San Francisco, CA 94143 USA
[4] Univ Virginia, Dept Radiol, Charlottesville, VA USA
[5] SUNY Upstate, Dept Radiol, Syracuse, NY USA
[6] Kaiser Permanente Los Angeles Med Ctr, Dept Vasc & Intervent Radiol, Los Angeles, CA 90027 USA