Figure 13. Quantitative evaluation of glycosaminoglycan content in cartilage with delayed gadolinium-enhanced imaging. Top: Delayed gadolinium-enhanced image maps T1 to glycosaminoglycan (GAG) content and shows a focal area of low glycosaminoglycan concentration (arrow). Bottom: Photograph of the specimen after staining with toluidine blue shows a focal area of cartilage damage (arrow). (Reprinted, with permission, from reference 73.)