Magic Angle Effect Plays a Significant Role in T1rho Relaxation in Articular Cartilage

Pedram Golnari¹, Jiang Du¹, Won C. Bae¹, Reni Biswas¹, Sheronda Statum¹, Eric Chang¹, Christine Chung¹

In recent years quantitative imaging of the joint tissues has focused on two particular biomarkers: T1rho and T2. T1rho has been shown to be sensitive to proteoglycan depletion . T2 has been shown to be sensitive to collagen matrix degradation. The magic angle effect is a potential confounding factor in T2 and T1rho evaluation of joint tissue degeneration. However, the literature regarding T1rho relaxation is inconsistent, with some groups finding strong residual dipolar interaction, and other groups reporting a much reduced magic angle effect. In this study we aimed to evaluate the effect of sample orientation on T2 and T1rho values of cadaveric human patellae.