Background/Purpose: Almost all previous clinical trials investigating the drug efficacy in patients with rheumatoid arthritis (RA) on the outcome of MRI were based on scans of a unilateral hand (unilateral approach). The aim of this study is to identify the usefulness of MRI scanning bilateral hands (bilateral approach) of patients with RA in clinical practice.

Methods: Thirty-five RA patients participated in this prospective study and received intravenous abatacept treatment for 12 months. MRI of bilateral hands was performed at baseline and 12 months. MRI images were scored for synovitis, osteitis and bone erosion according to the Rheumatoid Arthritis MRI Scoring System (OMERACT-RAMRIS). Score of unilateral hand was defined as score of hand with higher synovitis score. The smallest detectable changes (SDCs) in MRI scores were calculated to estimate the measurement error and a definite change of MRI score (progression or regression) was defined as a change in the score greater than the SDC cut-off. First, we compared MRI scores between hands at baseline and explored imbalances in the imaging scores for each hand. Next, we compared the treatment results obtained by MRI with the “bilateral approach” to those obtained by MRI with the “unilateral approach”.

Results: Imbalances in the synovitis, osteitis, and erosion scores were identified at baseline in 14%, 51%, and 40% of enrolled patients, respectively. We also found that the hand with the higher synovitis score was different from the hand with the higher osteitis score in 11% of patients and from the hand with the higher erosion score in 37% of patients. After 12-month treatment, higher number of patients with progressive synovitis and osteitis scores was detected in the “bilateral approach” than was detected in the “unilateral approach” (synovitis; one case in the “unilateral approach” /four cases in the “bilateral approach”, osteitis; none case /one case, respectively). No significant difference between two approaches was observed. The number of patients with progressive erosion scores was same (six cases in both approaches).

Conclusion: Our data revealed that high prevalence of imbalances in MRI scores between hands and that MRI by the “bilateral approach” revealed higher number of patients who showed progressions in synovitis and osteitis scores compared to the “unilateral approach”. These results imply that MRI of unilateral hands could make clinicians fail to detect joint damage of the other hand and that scanning bilateral hands provides more reliable information about joint damage of patients with RA in clinical practice.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/mri-of-bilateral-hands-prevents-clinicians-from-failing-to-detect-joint-damage-of-patients-with-rheumatoid-arthritis-compared-to-scanning-unilateral-hand/