1. Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
2. Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
3. Department of Veterinary Clinical Sciences, University of Minnesota, Saint Paul, MN, USA
4. Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
5. Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
6. Department of Diagnostic Radiology, University of Oulu, Oulu, Finland
7. Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA