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

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.

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.

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.

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%.