Background In chronic inflammatory conditions, the need for a more objective measurement of disease activity has been identified. Imaging biomarkers based on the automated quantification of dynamic contrast enhanced magnetic resonance images (DCE-MRI) have been studied in adult patients with rheumatoid arthritis (RA)1. In children with juvenile idiopathic arthritis (JIA) similar knowledge is very limited.
Objectives To compare treatment changes of clinical scores in patients with JIA and automated DCE-MRI quantitative parameters analysed with a dedicated software - Dynamikatm.
Methods In 8 Caucasian patients (7 girls, median age 13,6 years) with polyarticular JIA, who underwent standardized DMARD treatment, DCE-MRI of the metacarpophaleangeal (MCP) 2–5 joints in the most affected hand were performed at 3 time points: baseline (BL), month 3 and 6 of treatment using 0.2 Tesla Esaote C-Scan. Clinical scores included active joints (AJ), swollen joints (SJ), tender joints (TJ) and joints with limited range of motion (LJ) divided into 3 levels: joint level (the MCP), region level (the hand) and global level (all joints). DCE-MRI were analyzed using a region of interest covering synovium of MCP 2–5. Output parameters included DEMRIQ-ME (Maximum Enhancement) and -IRE (Initial Rate of Enhancement). DEMRIQ is a perfusion/inflammation imaging biomarker and combines the volume of synovial inflammation (GD-map based statistics) and the degree of perfusion (ME-map or IRE-map based statistics), either as volume (classified pixels) or intensity (ME/IRE) or a combination of both (DEMRIQ score).
Differences in DEMRIQ scores between visits, were analyzed using the t-test (p<0.05 = statistically significant, p<0.25 = clinically meaningful). Correlations were also assessed using the Pearson's Correlation Coefficient.
Results At 3 months all patients showed statistically significant and/or clinically meaningful changes mainly in DEMRIQ-ME, 6 patients in parallel with clinical improvement. Two patients worsened in DEMRIQ-ME despite clinical improvement. At 6 months, six patients continued clinical improvement. In all but one, DEMRIQ-ME persisted or worsened (compared to previous examinations) and patients had a clinical flare within 2 to 6 months after last DCE-MRI. One patient had persistent clinical activity with corresponding DEMRIQ-ME score. Another patient showed clinical worsening and improvement in DEMRIQ-ME, where clinical improvement followed later during disease course. Thus a persistent/rising DEMRIQ-ME compared to previous examinations predicted clinical flare in a timeframe between 2 and 6 months after last DCE-MRI, despite of global clinical improvement.
Conclusions Dynamika based scores (mainly DEMRIQ-ME) show to be useful for depicting disease activity in JIA. In particular, the DEMRIQ-ME correlated with clinical activity over time especially after 3 months. Moreover, persistence or worsening of Dynamika based scores could predict clinical flares (in this study within 2–6 months) despite of global clinical improvement. Dynamika based DCE-MRI calculations could be of high importance for disease management and a supportive tool in treatment decisions in pediatric rheumatology.
Eur J Radiol. 2010 Jun;74(3):e67–72.
Disclosure of Interest N. Tzaribachev Grant/research support from: UCB, Janssen, Pfizer, Roche, R. Hagoug Employee of: Image Analysis Ltd, P. Louka Employee of: Image Analysis Ltd, C. Trentin Employee of: Image Analysis Ltd, O. Kubassova Employee of: Image Analysis Ltd, M. Hinton Employee of: Image Analysis Ltd, M. Boesen: None declared