Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group

TY - JOUR

T1 - Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group

AU - Rudwaleit, M

AU - Jurik, A G

AU - Hermann, K-G A

AU - Landewé, R

AU - van der Heijde, D

AU - Baraliakos, X

AU - Marzo-Ortega, H

AU - Østergaard, Mikkel

AU - Braun, J

AU - Sieper, J

N1 - Keywords: Bone Marrow Diseases; Diagnosis, Differential; Edema; Humans; Magnetic Resonance Imaging; Osteitis; Sacroiliac Joint; Spondylarthritis; Synovitis

PY - 2009

Y1 - 2009

N2 - BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis and to reach consensus on which MRI findings are essential for the definition of sacroiliitis. METHODS: Ten doctors (two radiologists and eight rheumatologists) from the ASAS/OMERACT MRI working group reviewed and discussed in three workshops MR images depicting sacroiliitis associated with SpA and other conditions which may mimic SpA. Descriptions of the pathological findings and technical requirements for the appropriate acquisition were formulated. In a consensual approach MRI findings considered to be essential for sacroiliitis were defined. RESULTS: Active inflammatory lesions such as bone marrow oedema (BMO)/osteitis, synovitis, enthesitis and capsulitis associated with SpA can be detected by MRI. Among these, the clear presence of BMO/osteitis was considered essential for defining active sacroiliitis. Structural damage lesions such as sclerosis, erosions, fat deposition and ankylosis can also be detected by MRI. At present, however, the exact place of structural damage lesions for diagnosis and classification is less clear, particularly if these findings are minor. The ASAS group formally approved these proposals by voting at the annual assembly. CONCLUSIONS: For the first time, MRI findings relevant for sacroiliitis have been defined by consensus by a group of rheumatologists and radiologists. These definitions should help in applying correctly the imaging feature "active sacroiliitis by MRI" in the new ASAS classification criteria for axial SpA.

AB - BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis and to reach consensus on which MRI findings are essential for the definition of sacroiliitis. METHODS: Ten doctors (two radiologists and eight rheumatologists) from the ASAS/OMERACT MRI working group reviewed and discussed in three workshops MR images depicting sacroiliitis associated with SpA and other conditions which may mimic SpA. Descriptions of the pathological findings and technical requirements for the appropriate acquisition were formulated. In a consensual approach MRI findings considered to be essential for sacroiliitis were defined. RESULTS: Active inflammatory lesions such as bone marrow oedema (BMO)/osteitis, synovitis, enthesitis and capsulitis associated with SpA can be detected by MRI. Among these, the clear presence of BMO/osteitis was considered essential for defining active sacroiliitis. Structural damage lesions such as sclerosis, erosions, fat deposition and ankylosis can also be detected by MRI. At present, however, the exact place of structural damage lesions for diagnosis and classification is less clear, particularly if these findings are minor. The ASAS group formally approved these proposals by voting at the annual assembly. CONCLUSIONS: For the first time, MRI findings relevant for sacroiliitis have been defined by consensus by a group of rheumatologists and radiologists. These definitions should help in applying correctly the imaging feature "active sacroiliitis by MRI" in the new ASAS classification criteria for axial SpA.

U2 - 10.1136/ard.2009.110767

DO - 10.1136/ard.2009.110767

M3 - Journal article

C2 - 19454404

SN - 0003-4967

VL - 68

SP - 1520

EP - 1527

JO - Annals of the Rheumatic Diseases

JF - Annals of the Rheumatic Diseases

IS - 10

ER -