Figure 2

Qualitative scoring of antigen-induced arthritis (AIA) stage using superparamagnetic iron oxide nanoparticles (SPION)-labeled macrophage and gadolinium chelate (Gd) signal in the synovium on days 6, 10 and 13 post-induction in the presence and absence of dexamethasone (Dexa). (A) T1-weighted MR images showing the diffuseness of the SPION signal in the synovium; MR image with diffuseness (i) score of 3 and (ii) score of 0. (B) Line graph showing the blinded scores of diffuseness of the Dexa-treated and untreated groups. (C) T1-weighted MR images showing the intensity of the SPION signal in the synovium; MR image with intensity (i) score of 3 and (ii) score of 0. (D) Line graph showing the blinded scores of intensity parameter of the Dexa-treated and untreated groups. (E) Post-Gd T1-weighted MR images showing synovial inflammation as a positive contrast; MR image with synovial inflammation (i) score of 3 and (ii) score of 0. (F) Line graph showing the blinded scores of synovial inflammation of the Dexa-treated and untreated groups. All data points are mean ± standard error of mean. B and D: n = 13 untreated controls and n = 15 Dexa-treated group, reduced to 6 and 8 on day 13. B: P=1x10−8 on day 6, D: P = 0.00008 on day 10 and 0.002 on day 13 compared to the untreated control group. F: n = 20 on day 3, n = 14 on day 13, divided between Dexa-treated and untreated. P = 0.00126 on day 6 compared to the untreated controls. Red and yellow arrows indicate the SPION regions of interest where the scoring criteria were assessed. MR, magnetic resonance.