1. Department of Radiology, Massachusetts General Hospital, A. A. Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, Massachusetts 02129, United States
2. Systems and Biomedical Engineering Department, Faculty of Engineering, Cairo University, Giza, 12613, Egypt
3. Sean M Healey & AMG Center for ALS, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, United States
4. Department of Biostatistics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
5. Department of PM&R, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, Massachusetts 02129, United States
6. Sanofi Genzyme, Cambridge, Massachusetts 02142, United States