OBJECTIVETo evaluate the correlation between T2* relaxation time and the pathological changes in the knee joint of patients with osteoarthritis (OA) and analyze the changes of T2* relaxation time in early cartilage injury.

METHODSSixty-two patients with OA in different phases underwent magnetic resonance imaging (MRI) of the knee and the articular cartilage T2* relaxation time was recorded, with 20 young healthy volunteers as the control group.

RESULTSPatients with mild OA showed significantly different T2* relaxation time for most of the articular cartilage from that of the healthy volunteers (P<0.05), but no such difference was found between serious OA group and the healthy volunteers. The change of T2* relaxation time of the cartilage was also associated with age, weight and body height, and the potential effects of other factors could not be excluded.

CONCLUSIONThe articular cartilage shows no obvious morphological changes in early OA of the knee, a stage characterized mostly by alterations of the tissue structure and compositions. Cartilage pathologies can be the most obvious on the weight-bearing surface of the medial condyle of the femur or in the patella. T2* relaxation time measurement can be helpful in the detection of early cartilage pathologies.