[1] Univ Penn, Med Ctr, Philadelphia, PA 19104 USA
[2] Good Samaritan Hosp, Dept Diagnost Imaging, San Jose, CA USA
[3] MGH, Charleston, MA USA
[4] Harvard Univ, Sch Med, Charleston, MA USA
[5] Med Coll Wisconsin, Dept Radiol, Milwaukee, WI 53226 USA
[6] Univ Western Ontario, London, ON N6A 3K7, Canada
[7] Yale Univ, Sch Med, Dept Diagnost Radiol, New Haven, CT 06510 USA
[8] So Illinois Univ, Sch Med, Dept Radiol, St Johns Hosp, Springfield, IL USA
[9] Univ Washington, Dept Neuroradiol, Seattle, WA 98195 USA
[10] Washington Imaging Associates, Chevy Chase, MD USA
[11] Univ Cologne, Dept Radiol, Lindenthal Cologne, Germany
[12] Washington Univ, Med Ctr, Mallinckrodt Inst Radiol, Neuroradiol Sect, St Louis, MO 63110 USA
[13] Univ Texas, MD Anderson Canc Ctr, Houston, TX 77030 USA
[14] Reg Diagnost Imaging Ctr, Bedford Hts, OH USA
[15] Univ Texas, Hlth Sci Ctr, Dept Radiol, San Antonio, TX 78284 USA
[16] Univ Tubingen, Radiol Klin, Abt Neuroradiol, D-7400 Tubingen, Germany
[17] Univ Minnesota, Dept Radiol, Minneapolis, MN 55455 USA
[18] Univ Pittsburgh, Presbyterian Univ Hosp, Med Ctr, Pittsburgh, PA USA
[19] Duke Univ, Med Ctr, Dept Radiol, Durham, NC 27710 USA
[20] Univ Chicago, Chicago, IL 60637 USA
[21] Univ Colorado, Hlth Sci Ctr, Denver, CO USA
[22] Univ Michigan, Dept Radiol, Ann Arbor, MI 48109 USA
[23] Mallinckrodt Inc, St Louis, MO 63134 USA