Comparative Study Of Magnetic Resonance Imaging Of Acute And Chronic Knee Joint Cartilage Injury

Objective: To evaluate the specificity,sensitivity and accuracy of two differentMagnetic resonance imaging(MRI)specific sequences(three dimensional fat suppress spoiled gradient recalled echo,3D-FS-SPGR and threedimensional fast imaging employing steady state acquisition,3D-FIESTA)in detection of knee joint cartilage injury compared with the arthroscopy findings.The T2 value of damaged cartilage and normal cartilage or acute and chronic articular cartilage injury are compared using T2-mapping sequence to investigate if there are differences in MRI imaging between acute and chronic knee joint cartilage injury.Methods:This study included 50 knee joint with acute articular cartilage injury or osteoarthritis that will undergo arthroscopy.Twenty knee joints had acute articular cartilage injury,and thirty knee joints had osteoarthritis.In addition,20 healthy individuals with normal knee joint were selected as control.The patients and healthy controls were examinated with MRI special sequences examination.Then combined the received image data with the post-processing images,and statistical analysis was done to evaluate the degree of knee joint cartilage injury and corresponding observed indicators.Results: Both of the 3D-FS-SPGR and 3D-FIESTA could show the articular cartilage injury and evaluate the degree of knee joint cartilage injury well,and the images by 3D-FS-SPGR were much clearer.The sensitivity of T2-mapping was higher,and it could diagnose the change in compsition of articular cartilage that didn't be detected by arthroscopy.However,T2-mapping's specificity was poor,which was difficult to evaluate the degree of articular cartilage injury.For the same knee,the T2 value of patella cartilage was lower than that of femoral and tibial plateau cartilage.Whereas there were not obvious differences between the average T2 value of tibial plateau and femoral cartilage.And the T2 value of damaged articular cartilage had no significant change in the same parts of the knee joint,wether it was caused by trauma or OA.Most of the acute articular cartilage injury was grade II or III,which could be found in the medial femoral condyles and the medial tibial condyles.Whereas the chronic articular cartilage injury was usually found in the medial femoral condyle and the medial tibial condyles,most of which was grade III or IV.Conclusions: 3D-FSPGR,3D-FIESTA and T2-mapping have their own advantages and disadvantages in showing knee joint cartilage injury,respectively.There are significant differences between the images of acute and chronic knee joint cartilage injury.