1 Department of Radiology, Division of Musculoskeletal Imaging & Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. ajhuang@mgh.harvard.edu.
2 Department of Radiology, Division of Musculoskeletal Imaging & Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA.