Abstract
The maturation of pig articular cartilage was followed by ^2^H inβphase double quantum filtered (IPβDQF) spectroscopic MRI, ^1^H T~2~ MRI, and ^23^Na DQF and triple quantum filtered MRS. The results all lead to the conclusion that the order and density of the collagen fibers in articular cartilage increase from birth to maturity. At birth, both ^2^H IPβDQF signal and ^1^H T~2~ were homogeneous throughout the cartilage and their values independent of the orientation of the plug relative to the magnetic field. At maturation, the ^2^H IPβDQF spectrum near the bone is composed of two pairs of quadrupolar split satellites and the ^1^H T~2~ relaxation is biexponential, indicating the presence of two groups of collagen fibers. The ^2^H satellites are orientation dependent, indicating that the two groups of fibers are well ordered at maturation. The fast component of ^1^H T~2~ is also orientation dependent and thus we have concluded that this component results from residual dipolar interaction, while the slow T~2~ component in mature cartilage, as well as the T~2~ relaxation in immature cartilage, is governed by other mechanisms. Magn Reson Med, 2006. Β© 2006 WileyβLiss, Inc.