Computer-Assisted Dynamic Contrast-Enhanced Magnetic Resonance Imaging Quantification Method for Assessment of Synovial Inflammation in Active Arthritis: Correlation With Synovial and Blood Biomarkers.

OBJECTIVE: To investigate the correlation and association between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantification (DEMRIQ) parameters with local and systematic markers of inflammation in patients with various etiologies of acute knee arthritis. METHODS: In a cross-sectional setting, patients with symptoms of acute knee arthritis underwent DCE-MRI, and DEMRIQ parameters were acquired. Markers of inflammation were obtained from the blood and synovial fluid through ultrasound-guided arthrocentesis of the affected joint. Spearman correlation and linear regression were performed to assess the correlation and association between DEMRIQ parameters and markers of inflammation, respectively. RESULTS: Forty-one patients, including 12 with rheumatoid factor-positive rheumatoid arthritis (RF+RA), 6 with rheumatoid factor-negative RA (RF-RA), 6 with psoriatic arthritis, 3 with reactive arthritis, and 14 with osteoarthritis (OA), were imaged. In the RF+RA group, all DEMRIQ variables correlated significantly with joint fluid interleukin-6 level (r ≥ 0.6) and number of neutrophils and polymorphonuclear (PMN) cells (r ≥ 0.8), whereas MExNvoxel and IRExNvoxel correlated with synovial inflammatory cells and blood C-reactive protein (CRP) levels (r ≥ 0.6). In patients with RF-RA, MExNvoxel correlated with blood CRP level (r = 0.8), joint fluid white blood cells, and neutrophils and PMN cells (r = 1). In the seronegative arthritis group, IRExNvoxel correlated with blood CRP, joint fluid PMN cells, and neutrophils (r ≥ 0.7). No significant correlation was seen in the OA group. There was a significant regression correlation between MExNvoxel and inflammatory infiltrates from joint fluid in RF+RA group (P < 0.05). CONCLUSION: DEMRIQ parameters exhibit varying relationships with local synovial and systemic inflammatory blood biomarkers across different etiologies of knee arthritis, which could provide insight into the level of inflammation in the affected joint.