Delayed gadolinium‐enhanced MRI of cartilage in the ankle at 3 T: Feasibility and preliminary results after matrix‐associated autologous chondrocyte implantation

Purpose: To demonstrate the feasibility of delayed gadolinium‐enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in the ankle at 3 T and to obtain preliminary data on matrix associated autologous chondrocyte (MACI) repair tissue. Materials and Methods: A 3D dual flip angle sequence was used with an eight‐channel multipurpose coil at 3 T to obtain T1 maps both pre‐ and postintravenous contrast agent (Magnevist, 0.2 mM/kg). Postcontrast T1 over time was evaluated in three volunteers; a modified dGEMRIC protocol was then used to assess 10 cases after MACI in the ankle. Results: Forty‐five minutes were found sufficient for maximum T1 decrease. MACI cases had a precontrast mean T1 of 1050 ± 148.4 msec in reference cartilage (RC) and 1080 ± 165.6 msec in repair tissue (RT). Postcontrast T1 decreased to 590 ± 134.0 msec in RC and 554 ± 133.0 msec in RT. There was no significant difference between the delta relaxation rates in RT (9.44 × 10 −4 s −1 ) and RC (8.04 × 10 −4 s −1 , P = 0.487). The mean relative delta relaxation rate was 1.34 ± 0.83. Conclusion: It is feasible to assess the thin cartilage layers of the ankle with dGEMRIC at 3 T; MACI can yield RT with properties similar to articular cartilage. J. Magn. Reson. Imaging 2010;31:732–739. © 2010 Wiley‐Liss, Inc.