Abstract
ObjectiveThe objective of this study was to assess the maturation of matrix-associated autologous chondrocyte transplantation (MACT) grafts up to 2 years after the surgery using gray-level co-occurrence matrix (GLCM) texture analysis of quantitative T(2) maps, compare the results with the microfracturing technique (MFX) control group, and relate these results to the morphological MOCART 2.0 score.DesignA subcohort of 37 patients from prospective, multi-center study underwent examination on a 3T MR scanner, including a T(2) mapping sequence at 3, 12, and 24 months after surgery. Changes between the time-points in the mean T(2) values and 20 GLCM features extracted from T(2) maps were assessed in repair tissue, tissue adjacent to the repair site, and the reference cartilage for both procedures.ResultsSignificant correlations were found between the MOCART 2.0 and GLCM features for both surgical procedures. There were no significant differences between MACT and MFX. We identified significant intra-group changes in T(2) and autocorrelation (3M-12M: P = 0.002; 3M-24M: P = 0.004), dissimilarity (3M-24M: P = 0.01), homogeneity (3M-24M: P = 0.013), and correlation (3M-24M: P = 0.036), sum average (3M-12M: P = 0.001; 3M-24M: P = 0.002), and information measure (3M-24M: P < 0.001) in the MACT repair tissue. MACT models revealed differences in GLCM between all combinations of ROI types at almost all time-points. In the case of MFX, the significant differences were mainly between repair and reference tissue at 12 months.ConclusionTexture analysis provides a useful extension to T(2) mapping. Texture features are correlated to the morphological outcome and reveal differences in the process of maturation between MACT and MFX.