Magnetic resonance imaging reflects articular cartilage degeneration caused by proteoglycan depletion in the rabbit knee / 中华风湿病学杂志

ABSTRACT

Objective To study the appearance of magnetic resonance imaging (MRI) in early stages of cartilage degeneration and to detect its values.Methods Intra articular injection of 5 units of papain causing a reversible loss of cartilage proteoglycan in the New Zealand rabbit knees.Rabbits were scanned with magnetic resonance imaging,using a 0 3 T Hitachi magnet with 16 cm coil.Gradient echo sequences and spin echo sequences were performed in the sagittal planes at 0,24,48 and 72 hours after intra injection of papain.Then signal intensity and thickness of cartilage were measured.The proteoglycan content was measured biochemically and histochemically.Results The cartilage thickness and signal intensity decreased significantly in treated knees compared with control knees at 24 and 48 hours ( P 0 05) after injection of papain.These changes on magenetic resonance (MR) images were consistent with the changes of proteoglycan concentration measured by biochemical analysis and histochemical staining of cartilage.Conclusion It is possible for MRI to detect the early stages of cartilage degeneration.