Footnotes

• Contributors PC conceived the idea for this study and devised the grading system. RG, PM, GJ, PL and ST facilitated 3 Tesla MRI set-up and data acquisition. KF and CS assisted with clinical monitoring and data acquisition. TI did the telephone survey. TI and PC graded MRI reports and analysed the data. PC and TI wrote the first manuscript draft. All authors contributed to manuscript revision and approve the final version. PC is the guarantor.

• Competing interests None declared.

• Patient consent Obtained.

• Ethics approval The review of clinical MRI radiology reports was a service evaluation/audit and neither this nor the telephone survey of current practices required formal REC review under current UK NRES guidance. The MARBLE study has prior ethics approval (REC Ref. 11/H0717/6).

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