Abstract：Objective: To study the imaging feature and pathologic basis of osteoarthritis(OA) of the rabbit by comparing the relationship between MRI grade and pathological grade of OA. Materials and Methods: Thirty-five healthy New Zealand rabbits were divided into five groups randomly, including normal control group, 2-weeks, 4-weeks, 6-weeks and 8-weeks groups respectively after transaction of anterior cruciate ligament to build OA model. MRI and pathological observation were carried out at corresponding time point. HE was performed to observe the histopathologic changes in the degenerative cartilage. Results: The cartilage showed high signal and high contrast on 3D-Watsc sequence. The damage of cartilage became more severe with time. The MRI grades showed good consistency with pathological grades(Kappa=0.80). The MRI grades were different between each group(P<0.05). No significant differences were found between control and 2-weeks group, 4-weeks and 6-weeks groups, 6-weeks and 8-weeks groups by multiple comparison(P>0.05). The differences between the other pairs were significant(P<0.05). Conclusion: The pathological grades and MRI grades of OA increase gradually with postoperative time. MRI 3D-Watsc is able to observe signal features which changes in early stage of OA.
2011, Vol. 22 
