1. Royal Brompton and Harefield Hospitals, Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK
2. Department of Experimental and Clinical Medicine, Magna Graecia University, 88100 Catanzaro, Italy
3. Division of Cardiovascular Medicine, Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
4. Divisions of Nuclear Medicine and Cardiothoracic Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
5. Department of Neuroscience, Imaging and Clinical Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
6. Department of Clinical and Experimental Medicine, University of Messina, 98122 Messina, Italy
7. Department of Biomedical and Dental Sciences and of Morphological and Functional Images, University of Messina, 98122 Messina, Italy
8. Department of Cardiovascular and Pulmonary Science, Catholic University of Sacred Heart, 00168 Rome, Italy
9. School of Biomedical Engineering and Imaging Sciences, Faculty of Life Sciences and Medicine, King’s College London, London WC2R 2LS, UK