1. From the Department of Radiology, Orthopedic University Hospital Balgrist, Zurich, Switzerland (T.J.D., C.K.P., S.B., R.S., C.W.A.P.); Division of Medical Physics, Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland (K.G.Z.); and Faculty of Medicine, University of Zurich, Zurich, Switzerland (T.J.D., C.K.P., K.G.Z., S.B., R.S., C.W.A.P.).