T-1 rho-relaxation in articular cartilage: Effects of enzymatic degradation

Spin-lattice relaxation in the rotating frame (T-1 rho) dispersion spectroscopy and imaging were used to study normal and enzymatically degraded bovine articular cartilage, Normal specimens demonstrate significant T-1 rho ''dispersion'' (similar to 60 to similar to 130 ms) in the 100 Hz to 9 kHz frequency range, Proteoglycan-degraded specimens have 33% greater T-1 rho values than collagen-degraded or normal samples, T-1 rho-weighted images reveal structure not found in conventional T-1- or T-2-weighted images, Our results suggest that T-1 rho measurements are selectively sensitive to proteoglycan content. The potential of this method in distinguishing the early degenerative changes in cartilage associated with osteoarthritis is discussed.