MRI-Based Synovial Iron Quantification Associates with Bone Erosion in Rheumatoid Arthritis
Abstract
1. Introduction
2. Materials and Methods
2.1. Patient Enrollment and Study Design
2.2. Data Collection
2.3. Iron Quantification in Synovial Fluid and Synovium
2.4. MRI Acquisition
2.5. Statistical Analysis
3. Results
3.1. Demographical and Clinical Characteristics
3.2. Quantitative MRI Assessment in RA Patients
3.3. MRI R2* Is a Practical Method to Quantify Iron Accumulation in RA Joints
3.4. Iron Overload in RA Joint Lesions Correlates with Structural Injury
3.5. Synovial Iron as an Independent Risk Indicator for Bone Erosion in RA
4. Discussion
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Abbreviations
| ACPA | anti-citrullinated protein antibodies |
| AUC | area under the curve |
| CRP | C-reactive protein |
| DAS28 | disease activity score in 28 joints |
| ESGAR | European Society of Gastrointestinal and Abdominal Radiology |
| ESR | erythrocyte sedimentation rate |
| FLS | fibroblast-like synoviocytes |
| GRE | gradient echo |
| HAQ | health assessment questionnaire |
| IDEAL-IQ | iterative decomposition of water and fat with the echo asymmetry and least-squares estimation quantitation |
| LIC | liver iron concentration |
| MRI | Magnetic Resonance Imaging |
| OA | osteoarthritis |
| OR | odds radios |
| RA | rheumatoid arthritis |
| RAMRIS | RA MRI scoring system |
| RF | rheumatoid factor |
| ROC | receiver operating characteristic |
| ROI | region of interest |
| SAR | Society for Abdominal Radiology |
| SD | standard deviation |
| SE | spin-echo |
| SF | Synovial fluid |
| SJC | swollen joint counts |
| T1 FS + C | T1-weighted fat suppression contrast-enhanced images |
| T2-FS | T2-weighted fat suppression |
| TJC | tender joint counts |
| VAS | visual analogue scale |
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| n | Value | |
|---|---|---|
| R2*, S−1, mean (S.D.) | 51 | 47.34 (16.83) |
| Synovial volume, mm3, mean (S.D.) | 51 | 2309.45 (1169.05) |
| Mean Joint space width, mm, mean (S.D.) | 51 | 2.64 (1.28) |
| Bone erosion, mm, mean (S.D.) | 51 | 2.95 (1.59) |
| Bone erosion, n (%) | 51 | 100.00% |
| No erosion, scale (%) | 0 | 0 (0.00%) |
| 1–10% of bone eroded, scale (%) | 3 | 1 (5.90%) |
| 11–20% of bone eroded, scale (%) | 9 | 2 (17.60%) |
| 21–30% of bone eroded, scale (%) | 22 | 3 (43.10%) |
| 31–40% of bone eroded, scale (%) | 6 | 4 (11.80%) |
| 41–50% of bone eroded, scale (%) | 4 | 5 (7.80%) |
| 51–60% of bone eroded, scale (%) | 3 | 6 (5.90%) |
| 61–70% of bone eroded, scale (%) | 3 | 7 (5.90%) |
| 71–80% of bone eroded, scale (%) | 1 | 8 (2.00%) |
| 81–100% of bone eroded, scale (%) | 0 | 9–10 (0.00%) |
| Synovitis, n (%) | 51 | 100.00% |
| No synovitis, scale (%) | 0 | 0 (0.00%) |
| 1–33% of synovitis, scale (%) | 5 | 1 (9.80%) |
| 34–66% of synovitis, scale (%) | 31 | 2 (60.80%) |
| 67–100% of synovitis, scale (%) | 15 | 3 (29.40%) |
| Bone marrow edema, n (%) | 41 | 80.40% |
| No BME, scale (%) | 10 | 0 (19.60%) |
| 1–33% of BME, scale (%) | 31 | 1 (60.80%) |
| 34–66% of BME, scale (%) | 9 | 2 (17.60%) |
| 67–100% of BME, scale (%) | 1 | 3 (2.00%) |
| Variables | Univariate Regression | Multivariate Regression | ||
|---|---|---|---|---|
| OR (95% CI) | p-Value | OR (95% CI) | p-Value | |
| Ages (years) | 1.128 (0.129, 9.857) | 0.914 | - | - |
| Female | 0.294 (0.077, 1.126) | 0.074 | - | - |
| BMI (kg/m2) | 0.437 (0.022, 8.687) | 0.587 | - | - |
| Disease duration (years) | 4.760 (0.739, 30.661) | 0.101 | - | - |
| CRP (mg/L) | 10.707 (1.362, 84.170) | 0.024 | 0.405 (0.033, 4.954) | 0.479 |
| ESR (mm/1 h) | 2.529 (0.477, 13.397) | 0.275 | - | - |
| DAS28-ESR | 3.286 (0.336, 32.185) | 0.307 | - | - |
| DAS28-CRP | 3.880 (0.444, 33.927) | 0.220 | - | - |
| HAQ | 19.496 (1.113, 341.625) | 0.042 | 99.713 (0.530, 178.058) | 0.126 |
| R2* (S−1) | 366.560 (21.396, 6279.830) | p < 0.001 | 2358.336 (79.306, 70,130.290) | p < 0.001 |
| Synovial volume (mm3) | 245.904 (13.028, 4641.389) | p < 0.001 | 1536.134 (46.123, 511,161.440) | p < 0.001 |
| Serum iron (μmol/L) | 1.153 (0.114, 11.626) | 0.904 | - | - |
| Serum ferritin (ng/mL) | 16.852 (0.698, 406.747) | 0.082 | - | - |
| Transferrin saturation (%) | 1.890 (0.107, 33.456) | 0.664 | - | - |
| Serum phosphorus (mmol/L) | 1.425 (0.072, 28.018) | 0.816 | - | - |
| Serum calcium (mmol/L) | 88.065 (0.601, 108.296) | 0.115 | - | - |
| 25 hydroxyvitamin D3 (nmol/L) | 1.232 (0.039, 39.196) | 0.906 | - | - |
| RF (IU/mL) | 4.492 (0.777, 25.982) | 0.093 | - | - |
| ACPA (RU/mL) | 0.293 (0.016, 5.435) | 0.410 | - | - |
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Share and Cite
Zhong, S.; Lin, C.; Ren, J.; Li, Y.; Dong, B.; Zhu, W.; Jiang, Y.; Liao, Z.; Zhang, Y.; Tu, L.; et al. MRI-Based Synovial Iron Quantification Associates with Bone Erosion in Rheumatoid Arthritis. Biomedicines 2026, 14, 749. https://doi.org/10.3390/biomedicines14040749
Zhong S, Lin C, Ren J, Li Y, Dong B, Zhu W, Jiang Y, Liao Z, Zhang Y, Tu L, et al. MRI-Based Synovial Iron Quantification Associates with Bone Erosion in Rheumatoid Arthritis. Biomedicines. 2026; 14(4):749. https://doi.org/10.3390/biomedicines14040749
Chicago/Turabian StyleZhong, Shuyuan, Churong Lin, Jianhua Ren, Yuhang Li, Bo Dong, Weihang Zhu, Yutong Jiang, Zetao Liao, Yanli Zhang, Liudan Tu, and et al. 2026. "MRI-Based Synovial Iron Quantification Associates with Bone Erosion in Rheumatoid Arthritis" Biomedicines 14, no. 4: 749. https://doi.org/10.3390/biomedicines14040749
APA StyleZhong, S., Lin, C., Ren, J., Li, Y., Dong, B., Zhu, W., Jiang, Y., Liao, Z., Zhang, Y., Tu, L., Zhao, M., Lin, D., Hu, K., Lu, C., Pan, Y., & Liu, Y. (2026). MRI-Based Synovial Iron Quantification Associates with Bone Erosion in Rheumatoid Arthritis. Biomedicines, 14(4), 749. https://doi.org/10.3390/biomedicines14040749

