T 2 mapping of healthy knee cartilage: multicenter multivendor reproducibility

[摘要] Background: T 2 mapping is increasingly used to quantify cartilage degeneration in knee osteoarthritis (OA), yet reproducibility studies in a multicenter setting are limited. The purpose of this study was to determine the longitudinal reproducibility and multicenter variation of cartilage T 2 mapping, using various MRI equipment and acquisition protocols. Methods: In this prospective multicenter study, four traveling, healthy human subjects underwent T 2 mapping twice at five different centers with a 6-month-interval. Centers had various MRI scanners, field strengths, and T 2 mapping acquisition protocols. Mean T 2 values were calculated in six cartilage regions of interest (ROIs) as well as an average value per patient. A phantom was scanned once at each center. To evaluate longitudinal reproducibility, intraclass correlation coefficients (ICC), root-mean-square coefficient of variation (RMS-CV), and a Bland-Altman plot were used. To assess the variation of in vivo and phantom T 2 values across centers, ANOVA was performed. Results: ICCs of the T 2 mapping measurements per ROI and the ROI’s combined ranged from 0.73 to 0.91, indicating good to excellent longitudinal reproducibility. RMS-CVs ranged from 1.1% to 1.5% (per ROI) and 0.6% to 1.6% (ROIs combined) across the centers. A Bland-Altman plot did not reveal a systematic error. Evident, but consistent, discrepancies in T 2 values were observed across centers, both in vivo and in the phantom. Conclusions: The results of this study suggest that T 2 mapping can be used to longitudinal assess cartilage degeneration in multicenter studies. Given the differences in absolute cartilage T 2 values across centers, absolute T 2 values derived from various centers in multicenter multivendor trials should not be pooled.

[学科分类] 外科医学

[关键词] Knee;cartilage;magnetic resonance imaging (MRI);T 2 mapping;reproducibility