Sodium NMR evaluation of articular cartilage degradation

One of the first effects of degenerative osteoarthritis is the loss of prot eoglycans from the matrix of articular cartilage. Using a model of osteoart hritic change where the cartilage has been enzymatically degraded with tryp sin, the sodium NMR characteristics of the cartilage were determined as a f unction of changes in the proteoglycan content. The results demonstrate tha t the single quantum sodium signal decreases as the proteoglycan content of the cartilage matrix decreases. In addition, the relaxation characteristic s of the sodium change such that the T-1 is longer, the T-2s is longer, and the T-2f is shorter. Short echo-time, T-1-weighted sodium images are prese nted which demonstrate that this information may be utilized to detect the loss of proteoglycans from articular cartilage. Magn Reson Med 41:30-34, 19 99, (C) 1999 Wiley-Liss, Inc.