“…In a study using excised human patella cartilage, Keenan et al [26] stated that T1 values reflect the change in GAG content more sensitively than T2 mapping. Our previous results also indicate that T1 mapping is more sensitive for detecting cartilage degeneration than T2 mapping [11,27]. The reason is that by applying the spin-lock pulse, T1 mapping can probe the interactions of protons between the bound water and the GAG, which is the earliest change in the ECM during cartilage degeneration [3,28,29].…”