What Are the Potential Roles Magnetic Resonance Imaging Can Play in Differentiated and Undifferentiated Arthritis?

Review Article

Y Emad¹, Y Ragab², I Bassyouni¹, H Darweesh¹, A Almansari⁴ and JJ Rasker³

Affiliations: ¹Rheumatology and Rehabilitation Department; ²Radiology Department, Faculty of Medicine, Cairo University, Cairo, Egypt; ³University Twente, Enschede, the Netherlands and ⁴Internal medicine department, Dr. Erfan and Bagedo general hospital, Jeddah, KSA

ABSTRACT

Magnetic resonance imaging (MRI) has advanced our understanding of many types of arthritis, with respect to both inflammatory processes and articular damage. The role of MRI in differentiating between different forms of arthritis is still debatable and under discussion. The current available data suggest that MRI can separate subsets of early synovitis patients on the basis of two principal imaging patterns: one in which the inflammatory changes are located primarily in the synovium; and another in which the periarticular entheses are inflamed in association with intense edema of the adjacent bone. These two patterns are proposed to broadly classify patients with early synovitis into an “RA” phenotype where synovitis is the primary process, and a “spondyloarthropathy” (SpA) phenotype where enthesitis is the primary process and synovitis occurs on a secondary basis. Enthesitis is a common feature on MRI in SpA, which can help to determine the evolving pattern of patients with undifferentiated arthritis of the knee joint, and may have important clinical implications for classification purposes.

Keywords: enhanced magnetic resonance imaging (MRI), undifferentiated arthritis,
knee enthesitis, rheumatoid arthritis, seronegative spondylarthropathy (SpA)
Correspondence: Yasser Emad, Rheumatology and Rehabilitation Department, Faculty of Medicine, Cairo University, Cairo, Egypt. Rheumatology and Rehabilitation Department Dr Erfan and Bagedo General Hospital, Jeddah, KSA. e‐mail: Yasseremad68@yahoo.com