Orrin M Troum, MD

Orrin M Troum, MD, FACR


Dr Troum is a Clinical Professor of Medicine, Division of Rheumatology, at the Keck School of Medicine, University of Southern California. Dr Troum received his BS degree in biology at Tulane University, New Orleans, LA. He attended the Autonomous University of Guadalajara, School of Medicine and the College of Medicine and Dentistry of New Jersey prior to completing his internship/residency in internal medicine and fellowship in rheumatology at Los Angeles County/USC Medical Center. He is board certified in internal medicine and rheumatology and is also a certified clinical densitometrist by the International Society of Clinical Densitometry.

Dr Troum pioneered the use of extremity MRI in the evaluation, clinical decision process and outcome of patients with inflammatory arthritis. He is a founding member and treasurer of the International Society of Extremity MRI in Rheumatology.  He serves on the board of directors of the Intersocietal Commission for the Accreditation of Magnetic Resonance Laboratories (ICAMRL).  Dr Troum is a founding fellow of the American College of Rheumatology and a member of the Southern California Rheumatology Society (past president 1999-2000), California Rheumatology Alliance, Philadelphia Rheumatism Society, the American Society of Bone and Mineral Research and Osteoarthritis and Research Society International.

He served as a full-time faculty member (Acting Clinical Director of Rheumatology) at LAC/USC prior to starting his rheumatology private practice in 1986. He was a member of the board of directors (2003–2007) and is currently serving on the public policy & advocacy committee of the Arthritis Foundation’s largest US chapter in Southern California.

Dr Troum is the founder and medical director of the Westside Arthritis & Metabolism Center in Santa Monica, CA.  His clinical trial research focuses on rheumatoid arthritis and other inflammatory arthropathies, osteoarthritis, osteoporosis, and metabolic disorders.


  1. Troum Om, Olech E, Wells A. Newer Imaging Modalities: Their Use in Rheumatic Diseases Accepted for publication in Update Clinics of Rheumatic Diseases: 2011
  2. Troum OM, Peterfy C, Kaine J, Chung C, Anisfeld A, Olech E, Conagham PG: Baseline CRP predicts early improvement in Synovitis, Osteitis, and Erosions on MRI in Rheumatoid Arthritis patients treated with Tocilizumab: Results from the ACT-RAY Poster & Oral presentation: (Data Review Meeting:) ACR / ARHP Annual Scientific Meeting, Atlanta, GA Nov 7, 2010
  3. Troum OM, Peterfy C, Kaine J, Day B-M.M, Woodworth T, Conaghan PG: Tocilizumab Reduce Synovitis within 2 weeks and Pre-Erosive Osteitis within 12 weeks I Patients with RA: Results from a Multi-Site Low Field MRI Study EULAR – Oral Presentation. June 14-19, 2010  Rome, Italy
  4. Wyman B, Zhang Y, Bloom JB, Troum OM, Fatemi N, Wu S, Totterman S, Bennett RE, Tengowski M.: Early Treatment Effects of  Anti-TNF Therapy on MRI. Poster presentation : ACR / ARHP Annual Scientific Meeting. October 18-21, 2009 Philadelphia, PA
  5. Chang J, Crues VJ, Troum OM: MRI in Rheumatoid Arthritis: Why Start Using it Now? A Review of Imaging Modalities, MR Scoring And Pathophysiology in RA: Contemporary Topics in Rheumatoid Arthritis, October 1, 2009-2010
  6. Troum OM: Newer Imaging Technology For The Diagnosis Of Early Rheumatoid Arthritis And Monitoring Of Inflammation And Joint Damage. Journal of Clinical Rheumatology 2007;13(5).
  7. Fleischmann R, Schiff M, Keystone E, Mease P, Troum OM, Weinblatt M: A New Composite Measure for Assessing RA  Activity in Clinical Practice: Poster Presentation: ACR Annual Scientific Meeting: November 2007, Boston, MA.
  8. Furst D, Gaylis N, Bray V, Olech E, Yocum D, Ritter J, Weisman M, Wallace D J, Crues JV III, Khanna D, Yeilding N, Callegari P, Visvanathan S, Rojas J, Hegedus R, George L, Mamun K, Gilmer K, Troum OM:  Open-label, pilot protocol of patients with rheumatoid arthritis who switch to infliximab after an incomplete response to etanercept: The Opposite Study. Ann Rheum Dis 2007;66:893-9.
  9. Chen TS, Crues JV, III, Ali M, Troum OM:  Detection of Changes in Size of Erosions in Rheumatoid Arthritis Using High Resolution In-Office MRI.  Journal of Rheumatology 2006;33:(10)1957-67.
  10. Furst DE, Yocum D, Weisman M, Troum OM, Bray V, Wallace D, Gaylis N,  Ritter J, Yeilding N, Gilmer K:  Infliximab Provides Additional Clinical and Radiographic Benefits in RA Patients Who Have an Inadequate Response to Etanercept: Poster presentation:  EULAR Annual Scientific Meeting.  June 2005 Vienna, Austria.
  11. Crues JV, Shellock FG, Dardashti S, James T, Troum OM. Identification of wrist and MCP joint erosions using a portable extremity MR system compared to conventional x-ray. Journal of Rheumatology, 2004;31:676-85.
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