[1] Stanford Univ, Sch Med, Dept Radiol, Neuroradiol Sect, Palo Alto, CA 94304 USA
[2] PLA Army Gen Hosp, Dept Neurol, Beijing, Peoples R China
[3] Stanford Univ, Dept Med, Quantitat Sci Unit, Palo Alto, CA USA
[4] Stanford Univ, Div Cardiovasc Med, Palo Alto, CA 94304 USA
[5] Stanford Univ, Sch Med, Dept Radiol, Cardiovasc Imaging Sect, Palo Alto, CA 94304 USA
[6] Univ Calif San Francisco, Dept Radiol, San Francisco, CA USA
[7] Weill Cornell Med, Dept Radiol, New York, NY USA
[8] Azienda Osped Univ Cagliari, Dipartimento Radiol, Cagliari, Italy
[9] Stanford Univ, Sch Med, Dept Med, Palo Alto, CA 94304 USA