Dynamic contrast-enhanced 3-T magnetic resonance imaging: a method for quantifying disease activity in early polyarthritis.

OBJECTIVE: To determine whether measurement of synovial enhancement and thickness quantification parameters with 3.0-Tesla magnetic resonance imaging (3-T MRI) can reliably quantify disease activity in patients with early polyarthritis.
MATERIALS AND METHODS: Eighteen patients (16 women, 2 men; mean age 46 years) with early polyarthritis with less than 12 months of symptoms were included. MRI examination using 3-T device was performed by a new approach including both wrists and hands simultaneously in the examination field-of-view. MRI scoring of disease activity included quantification of synovial enhancement with simple measurements such as rate of early enhancement (REE; REE(57) = S(57)/S(200), where S(57) and S(200) are the signal intensities 57 s and 200 s after gadolinium injection) and rate of relative enhancement (RE; RE = S(200) - S(0)). Both wrists and hands were scored according to the Rheumatoid Arthritis MRI Scoring System (RAMRIS) for synovitis. Disease activity was clinically assessed by the 28-joint Disease Activity Score (DAS28).
RESULTS: DAS28 score was strongly correlated with RE (r = 0.8331, p < 0.0001), REE (r = 0.8112, p < 0.0001), and RAMRIS score for synovitis (r = 0.7659, p < 0.0002). An REE score above 0.778 accurately identified patients with clinically active disease (sensitivity 92%; specificity 67%; p < 0.05). A statistically significant difference was observed in the RE, REE, and RAMRIS scores for synovitis between patients with active and inactive disease (p < 0.05).
CONCLUSIONS: Our findings support the use of 3-T dynamic contrast-enhanced MRI for precise quantification of disease activity and for discriminating active disease from inactive disease in early polyarthritis.