MRI-Based Synovial Iron Quantification Associates with Bone Erosion in Rheumatoid Arthritis

作者：Shuyuan Zhong, Churong Lin, Jianhua Ren, Yuhang Li, Bo Dong, Weihang Zhu, Yutong Jiang, Zetao Liao, Yanli Zhang, Liudan Tu, Minjing Zhao, Dongfang Lin, Ke Hu, Chenyang Lu, Yunfeng Pan, Yan Liu · 发表于：Biomedicines · 年份：2026 · DOI：10.3390/biomedicines14040749 · 研究领域：Rheumatoid Arthritis Research and Therapies、Bone and Joint Diseases、Radiomics and Machine Learning in Medical Imaging

Objective: To evaluate the utility of synovial iron quantification using Magnetic resonance imaging (MRI) in assessing structural joint damage in the knee of patients with rheumatoid arthritis (RA). Methods: This cross-sectional study employed a two-stage design. In the initial comparative stage, 6 patients with RA and 5 patients with osteoarthritis (OA) were recruited to compare synovial R2* values, a metric derived from iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation (IDEAL-IQ) MRI sequences representing synovial iron content. Following this, the RA cohort was expanded to a total of 51 patients to investigate the association between R2* values and clinical parameters, including disease activity and bone erosion. Synovial fluid iron levels were measured with an Iron Assay Kit and synovial iron deposits were semi-quantified via Prussian blue staining. Associations between R2* and clinical and laboratory parameters, including inflammatory factors and joint damage indices, were analyzed using Spearman’s rank correlation. Univariate and multivariate ordered logistic regression models were employed to identify factors associated with bone erosion severity. An R2*-based nomogram was developed and validated using receiver operating characteristic (ROC) analysis and calibration curves. Results: Synovial R2* values were significantly higher in RA patients than those with osteoarthritis (53.66 S−1 vs. 31.38 S−1, p < 0.05), cons...