Figure 14a. Delayed gadolinium-enhanced imaging after autologous chondrocyte implantation. GAG = glycosaminoglycan. (a) Coronal image obtained 2 months after implantation shows decreased glycosaminoglycan content (arrow) in part of the implant. (b) Sagittal image obtained 15 months after implantation shows almost normal levels of glycosaminoglycan (arrow) in part of the implant. This example shows the potential of MR imaging for monitoring the glycosaminoglycan content in a cartilage repair site over time. (Reprinted, with permission, from reference 74.)