Background: The advantage of ultrasound (US) and capability of dynamic evaluation can ‎improve the accuracy of US diagnoses of shoulder pain, especially when the cause is not ‎immediately apparent during a routine evaluation. The current research aimed to evaluate the ‎role of dynamic ultrasound as a non-invasive modality in diagnosis of shoulder impingement ‎syndrome in comparison to magnetic resonance imaging (MRI) findings.‎

Methods: Thirty-six patients with a clinical diagnosis of subacromial impingement were ‎involved in this cross-sectional study that conducted at Radiodiagnosis Department of Zagazig ‎University Hospital. Static and dynamic ultrasonography were performed to all cases in ‎addition to conventional MRI examination.‎

Results: Our results revealed that ultrasound had 100% sensitivity and specificity in detecting ‎supraspinatus tear when compared to conventional MRI. Also, ultrasound showed 100% ‎sensitivity and 86.7% specificity in detection of calcification in supraspinatus muscle when ‎compared to MRI. Ultrasound had 100% specificity and 80% sensitivity in detection of ‎infraspinatus tendenopathic changes. Also, ultrasound had 100% specificity and 87.5% ‎sensitivity in detection of tendenopathic changes in subscapularis tendon. Ultrasound shows ‎‎100% sensitivity and specificity in detecting biceps tenosynovitis and acromioclavicular joint ‎osteoarthritis when compared to conventional MRI. A statistically significant reduction of the ‎sub-acromial tunnel during active shoulder movement was found with mean difference 0.42 (P ‎‎<0.001).‎

Conclusion: For evaluating the shoulder impingement as well as the rotator cuff disorders, ‎ultrasound was found to be comparable to MRI. ‎