Footnotes

• Contributors JJT conceived the article and produced the initial draft. LCW inputted into initial draft, revised and approved the final article. SK, radiologist, helped select and add detail to the radiological image selected.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Provenance and peer review Not commissioned; internally peer-reviewed.