The zonal architecture of human articular cartilage described by T2 relaxation time in the presence of Gd-DTPA2-.

The depth-wise variation of T(2) relaxation time is known to reflect the collagen network architecture in cartilage, while the delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) technique is sensitive to tissue proteoglycan (PG) concentration. As the cartilage PG content varies along the tissue depth, the depth-dependent accumulation of the contrast agent may affect the inherent T(2) of cartilage in a nonconstant manner. Therefore, T(2) and dGEMRIC are typically measured in separate MRI sessions.

Human articular cartilage proteoglycans are not undersulfated in osteoarthritis.

Chondroitin sulfate is the major constituent of cartilage. Inadequate sulfate availability results in the production of undersulfated proteoglycans. In osteoarthritis, there is a net loss of articular cartilage proteoglycans.

Evaluation of cartilage repair in the distal femur after autologous chondrocyte transplantation using T2 relaxation time and dGEMRIC.

Objectives: To investigate the potential of combining T2 relaxation time and delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) measurements after autologous chondrocyte transplantation (ACT).

Materials And Methods: T2 and dGEMRIC maps were measured in the sagittal and coronal directions in 12 patients 10-15 months after ACT surgery. Grafts were assessed for bulk full thickness, superficial and deep tissue T2 and dGEMRIC values, and were compared to control cartilage.

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 characteristics of human knee articular cartilage: topographical variation and relationships to mechanical properties.

The macromolecular structure and mechanical properties of articular cartilage are interrelated and known to vary topographically in the human knee joint. To investigate the potential of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1, and T2 mapping to elucidate these differences, full-thickness cartilage disks were prepared from six anatomical locations in nonarthritic human knee joints (N = 13). Young's modulus and the dynamic modulus at 1 Hz were determined with the use of unconfined compression tests, followed by quantitative MRI measurements at 9.

Speed of sound in normal and degenerated bovine articular cartilage.

The unknown and variable speed of sound may impair accuracy of the acoustic measurement of cartilage properties. In this study, relationships between the speed of sound and cartilage composition, mechanical properties and degenerative state were studied in bovine knee and ankle cartilage (n = 62). Further, the effect of speed variation on the determination of cartilage thickness and stiffness with ultrasound (US) indentation was numerically simulated.