1. Department of Emergency Medicine, Leeds Teaching Hospitals NHS Trust, Leeds, UK
2. Translational Anaesthesia and Surgical Sciences, Leeds Institute of Biomedical and Clinical Sciences, School of Medicine, University of Leeds, UK
3. Department of Radiology, Leeds Teaching Hospitals Trust, Leeds, UK
4. Leeds Institute of Medical Education, School of Medicine, University of Leeds, UK
5. Department of Emergency Medicine, Mid-Yorkshire NHS Trust, Dewsbury, UK