Imaging sequence and gender impact on quantitative MRI thresholds for traumatic bone oedema.

Motivation: Stress fractures are common in athletic populations causing significant time-lost and potential future complications. Quantitative MRI thresholds have gained popularity but indiscriminate use without careful validation may cause error. Goal(s): Evaluate impact of imaging sequence, age and gender on diagnosis of traumatic bone oedema. Approach: Lumbar MRI from high risk screening and symptomatic injuries were imaged using multiple fat-suppressed sequences. A modified water-fat phantom was built mimicking normal and abnormal bone composition. Results: Up to two-fold variation was evident in signal intensity of oedema between different fat-suppressed sequences, even when normalised. Female athletes showed higher signal intensities but age was not significant. Impact: Sequence and gender-dependence on bone signal have important clinical implications for the use of absolute intensity or ratios to quantify oedema. Clinical adoption requires more attention to standardisation, calibration or locally derived thresholds to avoid misdiagnosis.