Quantitative T2 mapping of matrix-associated autologous chondrocyte transplantation at 3 Tesla: an in vivo cross-sectional study.

OBJECTIVES To evaluate magnetic resonance (MR) T2 mapping for characterization of cartilage repair tissue following matrix-associated autologous cartilage transplantation (MACT). MATERIALS AND METHODS Fifteen patients were evaluated following MACT using a 3T MR scanner. Patients were categorized into 2 postoperative intervals: I: 3-13 months, II: 19-42 months. Mean T2 relaxation times calculated from multiple spin-echo sequence were determined in regions of interest (MACT and normal hyaline cartilage) and T2 line profiles through the repair tissue and control sites were acquired. RESULTS Mean global T2 values of repair tissue in group I were significantly higher than at control sites (P < 0.05). Repair tissue in group II showed no significant difference to control sites. Repair tissue T2 line profiles normalized over time toward the control sites. CONCLUSIONS T2 mapping allows visualization of cartilage repair tissue maturation. Global T2 repair tissue values approach that of control sites after more than 1.5 years, similar behavior is seen in the zonal organization.