1. Department of Radiology, Neuroradiology Section; Stanford University School of Medicine; Palo Alto CA
2. Department of Neurology; PLA Army General Hospital; Beijing China
3. Department of Medicine, Quantitative Sciences Unit; Stanford University School of Medicine; Palo Alto CA
4. Division of Cardiovascular Medicine; Stanford University; Palo Alto CA
5. Department of Radiology, Cardiovascular Imaging Section; Stanford University School of Medicine; Palo Alto CA
6. Department of Radiology; University of California San Francisco; San Francisco CA
7. Dipartimento di Radiologia; Azienda Ospedaliero Universitaria di Cagliari; Cagliari Italy
8. Department of Medicine; Stanford University School of Medicine; Palo Alto CA