T1rho Dispersion and T2 Measurements of Cartilage and Muscle in Guinea Pig Knees at 7 Tesla

Gerd Melkus¹, James Hawkins¹, Joseph Schooler¹, Xiaojuan Li¹, Sharmila Majumdar¹

3D T1rho dispersion measurements using different spin-lock field strengths (B₁ = 0.5, 1, 2, 4, 6 kHz) and T2 mapping were performed in vivo on the knee joint of male Dunkin Hartley guinea pigs at two different ages (3 months and 13 months) at 7T. While T1rho of the muscle and cartilage increases with increasing B₁-field in all four animals, T1rho values differ between age groups. There is the evidence that a more sensitive interpretation of the cartilage status can be achieved when higher B₁ -fields (4 kHz or above) are applied for in vivo T1rho mapping.