Non-contrast Imaging of Knee Synovitis in Rheumatoid Arthritis: Comparison of T1 and T2 Mapping with Dynamic Contrast-Enhanced MRI

Motivation: Dynamic contrast-enhanced (DCE)-MRI can quantify synovial inflammation (synovitis) in rheumatoid arthritis (RA) but requires intravenous contrast administration. Non-contrast T1 mapping has recently been proposed as an alternative for synovitis evaluation. Goal(s): This study aims to quantify T1 and T2 values in the synovium of RA patients with synovitis and correlate them with DCE-MRI parameters. Approach: Eight RA patients underwent 3T MRI to quantify T1, T2, and DCE-MRI parameters in synovium regions segmented on T1- and proton-density-weighted images. Results: Synovium T1 values correlated positively with DCE-MRI parameters highlighting the potential of T1 mapping as a non-contrast alternative to DCE-MRI for assessing knee synovitis. Impact: This study highlights the potential of T1 mapping as an alternative to contrast-enhanced MRI for assessing knee synovitis in patients with rheumatoid arthritis. T1 mapping may facilitate broader evaluation of knee synovitis, especially in patients with contraindications to contrast-enhanced MRI.