Fig. 1.

RF pulse sequence and sodium magnetization evolution during the IR sequence. A and C: Fluid sodium (T₁ = 43 ms and ${\text{T}}_2^{\ast }=20\text{ms}$) with the rectangular pulse (with TI = 29 ms) and WURST pulse (with TI = 27) respectively. B and D: Cartilage sodium short component (T₁ = 26 ms and ${\text{T}}_2^{\ast }=5\text{ms}$) with the rectangular pulse and WURST pulse respectively, and the same TI as for fluid sodium.