1. Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute National Institutes of Health Bethesda Maryland USA
2. Siemens Medical Solutions USA Inc. Malvern Pennsylvania USA
3. Siemens Healthcare GmbH Erlangen Germany
4. Critical Care Medicine Department, Clinical Center National Institutes of Health Bethesda Maryland USA
5. Department of Radiology and Imaging Sciences, Clinical Center, Department of Health and Human Services National Institutes of Health Bethesda Maryland USA