1. Department of Radiology, Stanford University, Stanford, California
2. Stanford Cardiovascular Institute, Stanford University, Stanford, California
3. Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
4. Department of Physiology, University of Auckland, Auckland, New Zealand
5. Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
6. Department of Biomedical Engineering, King’s College London, London, United Kingdom
7. Veterans Administration Palo Alto Health Care System, Palo Alto, California