Purpose: To assess the diagnostic accuracy of double inversion recovery (DIR) magnetic resonance imaging (MRI) sequences for synovitis of the wrist joints in patients with rheumatoid arthritis (RA).
Material and methods: Participants with newly diagnosed RA were enrolled between November 2019 and November 2020. MRI examinations of the wrist joints were performed using a contrast-enhanced T1-weighted imaging sequence (CE-T1WI) and DIR sequence. We measured synovitis score, number of synovial areas, synovial volume, mean synovium-to-bone signal ratio (SBR), and synovial contrast-to-noise ratio (SNR). The inter-reviewer agreement rated on a four-point scale was evaluated by calculating the weighted k statistics. Two MRI sequences were assessed using Bland-Altman analyses, and the diagnostic performance of DIR images was calculated using the chi-square test.
Results: A total of 47 participants were evaluated, and 282 joint regions in 5076 images were reviewed by two readers. There was no significant difference in synovitis scores (P = 0.67), number of synovial areas (P = 0.89), and synovial volume (P = 0.086) between the two MRI sequences. DIR images showed better SBR and SNR (all P < 0.01). There was good agreement between the two reviewers in terms of synovitis distribution (κ = 0.79). The synovitis was well agreed upon by the two readers according to Bland-Altman analyses. Using CE-T1WI as the reference standard, DIR imaging demonstrated a sensitivity of 94.1% and a specificity of 84.6% at the patient level.
Conclusion: The non-contrast DIR sequence showed good consistency with CE-T1WI and potential for evaluating synovitis in patients with RA.
Keywords: Double inversion recovery; Magnetic resonance imaging; Rheumatoid arthritis; Synovitis.
© 2023. Italian Society of Medical Radiology.