P Hogg1, F Alrehily2, C Sá Dos Reis3, C Buissink4, H Erenstein4, M Voet4. 1. School of Health and Society, University of Salford, Greater Manchester, UK. Electronic address: p.hogg@salford.ac.uk. 2. College of Applied Medical Sciences, Taibah University, Medina 42353, Saudi Arabia. 3. School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland (HES-SO), Av. de Beaumont 21, 1011, Lausanne, Switzerland. 4. Department of Medical Imaging and Radiation Therapy, Hanze University of Applied Sciences, Groningen, Netherlands.