Magnetic Resonance Imaging of Shoulder Pain Pathology

Background: The shoulder joint is structurally classified as a synovial ball and socket joint and functionally as a diarthrosis and multiaxial joint. It involves articulation between the glenoid cavity of the scapula (shoulder blade) and the head of the humerus (upper arm bone). Due to the very loose joint capsule that gives a limited interface of the humerus and scapula, it is the most mobile joint of the human body. MR imaging of the shoulder is widely used for assessment of impingement and instability-related clinical conditions. The complex anatomy of even small structures of the shoulder joint has gained more importance within the last two decades due to the increasing spatial resolution of MR imaging. Radiologists must be familiar with the normal anatomy, variations, and the prevalence of abnormal conditions in the shoulder. The following discussion addresses normal anatomy and variations. Shoulder pain is one of the most common musculoskeletal complaints. The shoulder is a complex structure consisting at its most basic level of two joints, one of which, the glenohumeral joint, is reinforced by a fibrocartilaginous labrum and is supported by multiple ligaments, muscles, tendons, and articular surfaces. Although each imaging modality used in the evaluation of the shoulder joint has strengths and weaknesses Shoulder pain affects work productivity, activities of daily life, and quality of life.The most common causes of chronic shoulder pain are reported to be: Rotator cuff and muscles pathology: A)Rotator cuff tendinopathy, B)Rotator cuff tear (partial and full thickness), C) Impingement syndromes, 2) Calcific tendinitis, 3) Adhesive capsulitis, 4) Paralabral cyst, 5)Acromioclavicular(AC) osteoarthritis, 6)Sub acromial subdeltoid (SASD) bursitis.Magnetic resonance imaging (MRI) is a crucial diag