Rate of Recommendation for Follow-up MRI Post-shoulder Ultrasound: An Initial Benchmarking Study.

RATIONALE AND OBJECTIVES: Ultrasound exhibits comparable accuracy to magnetic resonance imaging (MRI) for assessing many common shoulder pathologies. Despite this, many patients are being recommended for follow-up MRI after undergoing shoulder ultrasound. The purpose of this study is to offer an initial benchmark for an acceptable rate of recommendation for follow-up MRI following shoulder ultrasound.

MATERIALS AND METHODS: During a two-month period all diagnostic shoulder ultrasound imaging reports from a community radiology site were isolated (n = 350). Referrals were from a mixed base but predominantly Family Physicians. Reports containing the keywords MRI were manually reviewed and those recommending MRI follow-up were characterized according to their indication for additional imaging.

RESULTS: Of the 350 studies, 155 were interpreted by musculoskeletal fellows and 195 by staff radiologists. Additional MRI was recommended in 21 instances in total (6.0%) but 8.2% by staff radiologists. Reasons for additional imaging were further rotator cuff evaluation, poor visualization, evaluate internal derangement, post-vaccination pain, soft tissue mass evaluation, non-rotator cuff muscular injury, and fracture evaluation.

CONCLUSION: We propose that in a group with experience in musculoskeletal ultrasound (MSKUS) examining patients from a mixed referral base, the rate of recommendation for additional MRI should be less than 9%.