Hyaline cartilage: In vivo and in vitro assessment with magnetization transfer imaging

PURPOSE: To elucidate the magnetization transfer (MT) effects of major compone MATERIALS AND METHODS: The authors evaluated the MT effect of type II collagen and chondroitin sulfate phantoms (concentrations of 0.6%, 1.2%, 2.4%, 4.8%, 9.6%, and 19.2%), mass-cultured rat osteosarcoma-derived cells, and normal articular cartilage of the knee. RESULTS: The MT effect of collagen yielded a decrease in signal intensity of 10% (1.2% collagen) to 31% (19.2% collagen); the decrease varied linearly with collagen concentration. Chondroitin sulfate did not have a statistically significant MT effect. Cell pellets showed a decrease in signal intensity of 22%-26%, which was greater than that of 4.8% collagen. Normal articular cartilage of the knees showed a decrease in signal intensity of 38%-48%. CONCLUSION: The major role of collagen in MT contrast of hyaline cartilage was confirmed. In addition, a higher cellular contribution to the MT effect was also demonstrated.