Normal Shoulder MRI and MR Arthrography: Anatomy and Technique.

The use of MR for the diagnosis of shoulder lesions is well established, as well as MR arthrography for the diagnosis for shoulder instability and microinstability. For an accurate evaluation is essential to know the normal anatomy and variants to avoid the misdiagnosis of a pitfall as pathological condition. In addition we will discuss which variants might be clinically relevant. We will review the classical frequent variants such as intraarticular structures, especially glenohumeral ligaments and labrum but also bone, cartilage and rotator cuff variants and pitfalls. Both static and dynamic structures play an important role providing stability at different positions and with different range of motion.