Dr Andreas Helfen, MD, is a member of the “working group Cardiovascular Ultrasound” of the German Cardiac Society (GCS) and associate spokesman of the section “echocardiography” of the German Society of Ultrasound Medicine (DEGUM). He has been practising as a cardiologist since 2005 and in 2009 became the director of the echocardiography laboratory of the St.-Marien Hospital Lünen, an academic teaching hospital of the University of Münster. He performs more than 2000 echocardiographic examinations per year, including all advanced echocardiography methods. Since 2008 he organized more than 30 workshops on contrast echocardiography all over Germany and was invited as a speaker to national and international congresses. He is an approved course instructor of the German Society of Ultrasound Medicine (level III) and he has lectured in multiple stress echocardiography courses and stress refresher courses. In 2016 and in 2017 he was invited as a speaker and host to webinars of the European Association of Cardiovascular Imaging. In addition to his expertise in echocardiography Dr Helfen has gained extensive experience in interventional cardiology as well as in intensive care medicine. Dr Harald Becher, MD, PhD, former associate Professor at the University of Bonn and the chairman of the “working group Cardiovascular Ultrasound” of the German Cardiac Society (GCS) moved to Oxford, UK in 2001 and became Professor of Cardiac Ultrasound at Oxford University, and consultant cardiologist leading the echocardiography laboratory of the Oxford University Hospital. Since 2010 he is Professor of Medicine and the Heart and Stroke Foundation Chair for Cardiovascular Research at the University of Alberta, Canada. Dr Becher and his group belong to leaders in the development of contrast echocardiography and its implementation into clinical practice. Together with the physicist Peter Burns he wrote the first Handbook of Contrast Echocardiography and is one of the editors of theOxford Handbook of Echocardiography. Dr Becher is member of the writing committees of the American Society of Echocardiography and the European Association of Cardiovascular Imaging for recommendations of contrast agents in clinical practice. He is associate editor of Echocardiography and has written 10 book chapters and is the author of more than 140 scientific papers.