1. Department of Circulation and Medical Imaging Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway;
2. Norwegian National Advisory Unit on Ultrasound and Image-guided Therapy, St. Olavs Hospital, Trondheim, Norway;
3. Department of Health Research - Medical Technology, SINTEF, Trondheim, Norway;
4. Department of Radiology, St. Olavs Hospital, Trondheim, Norway