Ultrasound of the shoulder.

Ultrasonography (US) is a helpful imaging tool in the evaluation of the musculoskeletal system. It has some advantages over the other imaging techniques, such as plain radiography, computed tomography and magnetic resonance imaging, represented by the non-invasiveness and multiplanar imaging capability, repeatability, lack of radiation burden, good patient acceptance, and relatively limited costs. US offers an excellent resolution and a possibility for real-time dynamic examination of the joints and surrounding soft tissues, as well as enables monitoring of therapeutic response. The most common clinical indications for US examination of the shoulder are rotator cuff and biceps tendon pathology (tenosynovitis, tendinosis, complete and partial tears, and impingement) and disorders of other soft-tissue structures (joint recesses, bursae, muscles, suprascapular and axillary nerves) as well as bony cortex abnormalities. US is very useful for US-guided procedures (biopsy, joint and bursae aspirations and injections, aspiration and dissolution of calcific tendinosis). The aim of this article is to analyze the current literature about US of the shoulder and to describe both normal and pathological findings.