Affiliations:
1- Department of Otolaryngology-Head and Neck surgery, University Hospitals of North Midlands NHS Trust, Royal Stoke University Hospital, Stoke-on-Trent, United Kingdom.
2- Radiology Department, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Trust, Queen Victoria Road, Newcastle upon Tyne, United Kingdom.
3- School of Medicine, Keele University, Stoke-on-Trent, United Kingdom.