1. MR Center of Excellence, Medical University of Vienna, Vienna, Austria
2. Centre for Biomedical Engineering and Physics, Medical University of Vienna, Vienna, Austria
3. Institute for Clinical Diabetology, German Diabetes Center, Department of Metabolic Diseases, Heinrich-Heine University, Düsseldorf, Germany
4. Karl-Landsteiner Institute of Endocrinology and Metabolism, Vienna, Austria
5. Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.