USMSIT/NMUSIT Fundamental Guide on Diagnostic and Interventional Shoulder Ultrasonography

High-resolution ultrasound (US) has become an indispensable tool in evaluating and managing shoulder pain. It offers real-time visualization of tendons, ligaments, bursae, and joint recesses while enabling dynamic assessment and image-guided intervention. Building on the EURO-MUSCULUS/USPRM framework, this guideline presents a standardized, anatomy-based approach to diagnostic and interventional shoulder ultrasonography. Developed under the educational mission of the Ultrasound and Musculoskeletal/Neuromuscular Sonography Initiative in Taiwan - through its flagship programs Ultrasound Musculoskeletal Workshop in Taiwan (USMSIT) and Neuromuscular Ultrasound Workshop in Taiwan (NMUSIT) - the protocol integrates didactic instruction, live demonstration, and structured hands-on training to ensure reproducible and clinically relevant examinations. The guideline details systematic scanning of the long head of the biceps, subscapularis, acromioclavicular joint, supraspinatus, infraspinatus, teres minor, and posterior glenohumeral joint. It is also supplemented by tripartite visual documentation comprising cadaveric dissection, regional illustrations, and paired US images from both high-end and handheld devices. Characteristic sonographic findings for common shoulder pathologies - including biceps peritendinous effusion, acromioclavicular arthropathy, calcific tendinopathy, rotator cuff tears, and subacromial-subdeltoid bursitis - are described. In addition, practical pearls for US-guided interventions such as the long head of the biceps tendon, acromioclavicular joint, subdeltoid bursa, and posterior glenohumeral injections are provided. Emphasizing the principle of "diagnosis ahead of intervention," this guideline bridges educational precision and procedural application-fostering consistent training as well as safer and more effective management of shoulder disorders. Its standardized image - anatomy framework further facilitates integration into artificial intelligence - assisted systems for automated view recognition and measurement. Therefore, it aims to advance clinical, educational, and research endeavors in musculoskeletal ultrasonography.