Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Development and Validation of an MRI Joint Space Narrowing Score for Use in Rheumatoid Arthritis: A Potential Adjunct to the OMERACT RA MRI Scoring System.

Ostergaard4,  Mikkel, Boyesen5,  Pernille, Eshed10,  Iris, Gandjbakhch7,  Frédérique, Lillegraven5,  Siri, Bird6,  Paul, Foltz8,  Violaine

Chapel Allerton Hospital, Leeds, United Kingdom
Sheba Medical Centre, Tel Aviv University, Tel Aviv, Israel
Spire Sciences LLC, Kentfield, CA
St. George Hospital, University of NSW, Sydney, Kogarah, Australia
University of Auckland School of Medicine, Auckland, New Zealand
University of California San Francisco, Tiburon, CA
University of Leeds, Leeds, UK
University of Rochester, Rochester
Charité University Hospital, Berlin, Germany
Copenhagen University Hospitals at Hvidovre and Glostrup, Denmark
Copenhagen University Hospitals at Hvidovre and Glostrup, Hvidovre, Denmark
Diakonhjemmet Hospital, University of Oslo, Oslo, Norway
Division of Medicine, St. George Hospital, University of NSW, Sydney, Australia
Hôpital Pitié-Salpétrière, Université PARIS VI-UPMC, Paris, France
Hôpital Pitié-Salpétrière, Université PARIS VI-UPMC, Paris, France
Maastricht University Hospital, Maastricht

Background:

Magnetic resonance imaging (MRI) is now frequently being used as an outcome measure in rheumatoid arthritis (RA) clinical trials. The OMERACT RA MRI score (RAMRIS), evaluating bone erosions, bone oedema and synovitis, is generally used in such trials.

Cartilage damage is an important aspect of structural joint damage in RA, and a reliable MRI assessment system of joint space narrowing (JSN), reflecting cartilage damage, would further improve the usefulness of MRI in RA clinical trials.

Objective:

The aim of the present initiative was to develop and validate an OMERACT MRI assessment method of JSN in RA, which may be a useful adjunct to the current OMERACT RAMRIS.

Methods:

The project, which was undertaken by the OMERACT MRI in inflammatory arthritis group, had 3 phases:

Phase A: Exercise 1 (pilot study): Coronal T1weighted gradient echo MR images of unilateral wrist and MCP-joints from 5 RA patients and 3 controls were scored for JSN at 15 sites in the wrist and each of the 2nd-5th metacarpophalangeal (MCP), without reader pre-training or calibration, by 8 readers (7 readers read once, 1 reader twice), after circulation by DVD.

Phase B: Discussion, review of images and consensus on exact definition and scoring system.

Phase C (Exercise 2): Coronal T1-weighted 3D gradient echo images (voxel size 0.4×0.4×0.4 mm) MR-images of unilateral wrist and 2nd-5th MCP-joints of 15 RA (80% female; age: median 51 (33–78) y, disease duration 7 (4–22) y and 4 controls (75% female; age: median 36 (34–57) y) were scored using a revised score sheet (22 sites, Figure). MRI results were compared with radiographic JSN scores from the same hand (Sharp-van der Heijde method).

Intraclass correlation coefficients (ICCs; single/average measure used for intraobserver/interobserver agreements), and smallest detectable differences (SDDs, for mean of readings) were calculated.

Results:

Phase A: Interobserver agreement: ICC 0.93 and SDD 6.4 JSN units (9.9% of observed max). Intraobserver agreement: ICC 0.99 and SDD 2.8 JSN units (4.9% of observed max).

Phase B: Based on experiences from Phase A, agreement was reached on definition, scoring system, and reader rules (Figure).

Phase C: Interobserver agreement: ICC 0.92 and SDD 6.2 JSN units (8.7% of observed max). Intraobserver agreement: ICC 0.90 and SDD: 6.8 JSN units (11.0% of observed max). The correlation (ICC) with the Sharp-van der Heijde radiographic score of JSN in the same hand (which includes MCP-joints, PIP- joints and selected joint areas in the wrist, i.e. not exactly the same joints as the MRI score) was 0.77.

Conclusion:

An MRI scoring system of JSN in RA wrist and MCP joints was developed and showed good intra- and interreader agreements. The system may, after further validation in longitudinal data sets, be useful as an outcome measure of cartilage damage in RA, and may thereby further improve the usefulness of MRI in RA clinical trials.

To cite this abstract, please use the following information:
Ostergaard, Mikkel, Boyesen, Pernille, Eshed, Iris, Gandjbakhch, Frédérique, Lillegraven, Siri, Bird, Paul, et al; Development and Validation of an MRI Joint Space Narrowing Score for Use in Rheumatoid Arthritis: A Potential Adjunct to the OMERACT RA MRI Scoring System. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1369
DOI: 10.1002/art.29135

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