A Multireader Reliability Study Comparing Conventional High-Field Magnetic Resonance Imaging with Extremity Low-Field MRI in Rheumatoid Arthritis

PAUL BIRD, BO EJBJERG, MARISSA LASSERE, MIKKEL ØSTERGAARD, FIONA McQUEEN, CHARLES PETERFY, ESPEN HAAVARDSHOLM, PHILIP O'CONNOR, HARRY GENANT, JOHN EDMONDS, PAUL EMERY, and PHILIP G. CONAGHAN

ABSTRACT.
The use of extremity low-field magnetic resonance imaging (E-MRI) is increasing, but relatively few data exist on its reproducibility and accuracy in comparison with high-field MRI, especially for multiple readers. The aim of this multireader exercise of rheumatoid arthritis wrist and metacarpophalangeal joints was to assess the intermachine (high vs low-field) agreement and to assess the interreader agreement on high and low-field images. Study findings suggested that E-MRI performs similarly to conventional high-field MRI regarding assessment of bone erosions. However, for synovitis and bone edema, considerable intermachine and interreader variability was found. Further studies are needed before recommendations on multireader E-MRI assessment of these pathologies can be given. (J Rheumatol 2007;34:854–6)

Key Indexing Terms:

EXTREMITY MAGNETIC RESONANCE IMAGING
HIGH-FIELD MRI
EROSIONS
SYNOVITIS
BONE EDEMA
RELIABILITY

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From the Department of Rheumatology, St. George Hospital, University of New South Wales, Sydney, Australia; Departments of Rheumatology and Radiology, Copenhagen University Hospitals at Herlev and Hvidovre, Copenhagen, Denmark; Department of Rheumatology, Auckland University, Auckland, New Zealand; Synarc Inc. and University of California, San Francisco, California, USA; Diakonhjemmet Hospital, University of Oslo, Oslo, Norway; and Department of Radiology, Chapel Allerton Hospital, and the Academic Unit of Musculoskeletal Disease, University of Leeds, Leeds, UK.

Dr. Bird and Dr. Ejbjerg contributed equally to the work.

P. Bird, BMed (Hons), FRACP, PhD, Grad Dip MRI, Senior Lecturer; M. Lassere, MB, BS, Grad Dip Epi, PhD, FRACP, FAFPHM, Associate Professor in Medicine, Department of Rheumatology, St. George Hospital, University of NSW; B. Ejbjerg, MD, PhD, Senior Registrar, Copenhagen University Hospital at Herlev; M. Østergaard, MD, PhD, DMSc, Professor in Rheumatology/Arthritis, Copenhagen University Hospitals at Herlev and Hvidovre; F. McQueen, MD, FRACP, Associate Professor in Rheumatology, Department of Rheumatology, Auckland University; C. Peterfy, MD, PhD, Chief Medical Officer, Synarc Inc; E.A. Haavardsholm, MD, Research Fellow, Diakonhjemmet Hospital, University of Oslo; P. O'Connor, MBBS, MRCP, FRCR, Consultant Skeletal Radiologist, Department of Radiology, Chapel Allerton Hospital; H. Genant, MD, FACR, FRCR, Professor of Radiology, University of California; J. Edmonds, MB, BS, MA, FRACP, Director, Professor of Rheumatology, Department of Rheumatology, University of NSW; P. Emery, MA, MD, FRCP, ARC Professor in Rheumatology; P.G. Conaghan, MBBS, PhD, FRACP, FRCP, Professor of Musculoskeletal Medicine, Academic Unit of Musculoskeletal Disease, University of Leeds.

Address reprint requests to Dr. P. Bird, Department of Medicine, University of New South Wales, Sydney, Australia. E-mail: p.bird@unsw.edu.au

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