Damage progression in a two-year study of RA patients: is there an advantage in the use of MRI over x-rays?

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Arthritis Rheum. 2004 May;50(5):1383-9.

Documenting damage progression in a two-year longitudinal study of

rheumatoid arthritis patients with established disease (the DAMAGE study

cohort): is there an advantage in the use of magnetic resonance imaging

as compared with plain radiography?

Bird P, Kirkham B, Portek I, Shnier R, F, Edmonds J, Lassere M.

St. Hospital, Belgrave Street, Kogarah, New South Wales 2217,

Australia. pcbird@...

OBJECTIVE: In early rheumatoid arthritis (RA), longitudinal studies have

demonstrated that magnetic resonance imaging (MRI) is more sensitive

than radiography in demonstrating progressive erosive joint damage. The

present study evaluated the progression of erosive damage in patients

with established RA by using limited field of view MRI and comparing the

results with those obtained by radiography. METHODS: MRI and

radiographic studies were available from 47 of 60 patients enrolled in a

2-year RA observational study. MRI of the metacarpophalangeal (MCP)

joints was performed at baseline and 2 years later, and a single

observer scored all of the MR images with the use of an MRI scoring

method developed by the Outcome Measures in Rheumatology Clinical Trials

MRI RA study group. MR images from 14 patients were reread by the same

observer after 1 week to assess intraobserver reliability. Radiographs

were obtained at baseline and at 2 years, and were scored by an observer

using the modification of the Larsen score. Radiographs from 14

patients were reread after 1 week to assess the intraobserver

reliability. The smallest detectable difference (SDD) was calculated for

the MRI scores, the total Larsen scores, and the Larsen scores of the

dominant-hand MCP joints (MCPs 2-5) for direct comparison with the MRI

results. RESULTS: The median disease duration was 5.1 years (range

0.5-29 years). Evidence of erosion progression was identified by MRI in

30 patients (64%). The SDD based on the intraobserver scores was

calculated as +/-3.25 units. Using this result, 11 patients (23%) showed

evidence of erosion progression on MRI that was greater than the SDD.

The SDD for progression based on the intraobserver total Larsen

radiographic scores was 0.77 units, and the SDD for the Larsen scores of

the dominant-hand MCP joints was 1.55 units. On the basis of these

results, radiographic progression was noted in 19 patients (40%) by the

total Larsen score and 7 patients (15%) by the dominant-hand MCP Larsen

score. The most striking finding was that although MRI and radiograph

scores identified a similar group of patients as having progression of

joint damage, the radiographs of both hands appeared to be more

responsive to change, albeit with the caveat that radiographic

progression was most marked outside the dominant-hand MCP joints.

CONCLUSION: There was no clear advantage of MRI with a limited field of

view as compared with radiographic imaging of both hands in detecting

progression of joint damage over 2 years in this group of patients with

established RA. The conclusion drawn from this study is not that

radiographs are better than MRI or vice versa, but that careful analysis

is required to determine the optimal imaging method, or combination of

imaging methods, for each study population, depending on the objective

and duration of the study.

PMID: 15146407

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