Footnotes

• Contributors PM conceived the idea; PM and DC took the lead in writing the manuscript; MC performed and interpreted the magnetic resonance exam; SG, GI and AA contributed to the final version of the manuscript; and ALM and EMdG supervised the project.

• 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.

• Patient consent for publication Parental/guardian consent obtained.