Relationship Between T2 Mapping Of Patella Cartilage And Clinical Symptoms In Patients With Knee Osteoarthritis And Its Influencing Factors

ObjectiveTo investigate the relationship between patellar cartilage T2 mapping and clinical symptoms,articular cartilage defects and bone marrow lesions in patients with knee osteoarthritis.Materials and MethodsSixty-one patients with symptomatic knee osteoarthritis conformed to the diagnosis criteria of American College of Rheumatology were collected from May 2016 to December 2017.All of patients underwent MRI examination,including T2WI,3D FSPGR and T2mapping to evaluate the patellar cartilage defect grade,and grade of bone marrow lesions.ROI was sketched on T2mapping images and T2 value of patellar cartilage was measured.Cases were divided into two groups according to the T2 value.All the indexes(age,sex,BMI grade,cartilage defect,bone marrow lesion,WOMAC pain score,WOMAC stiffness score and WOMAC joint dysfunction score)were compared between two groups using multivariate linear regression analysis of the above indicators and the correlation between them and T2 values.Variance analysis was used to determine the relationship between cartilage defects,bone marrow edema and T2 values,the Scatter plot maps of them were drew,and the linear correlation coefficient was calculated.P<0.05 for the difference was defined as statistically significant.Results The T2 value was in accordance with the normal distribution.According to the mean T2 value,the difference of cartilage defect and bone marrow injury was statistically significant(P<0.001 and 0.043,respectively)between two groups,but there were no significant difference of age,gender,BMI grade,WOMAC pain score,WOMAC stiffness score and WOMAC joint dysfunction score(P>0.05).Multivariate linear regression analysis showed that the coefficient of determination R~2 was 0.565.According to the multiple regression hypothesis test results,P value<0.001,it can be considered that there is a linear relationship between the respective variables and the dependent variable(T2 value),cartilage defects and bone marrow lesions have linear relationship with T2 values,P values were<0.001 and 0.032 respectively.According to variance analysis,T2 values were different among different grades of cartilage defects and bone marrow lesions,the difference was statistically significant,P values were<0.001 and 0.004.There were positive correlation between cartilage defects,bone marrow lesions and T2 values,the correlation coefficients were 0.711 and 0.345,P values were<0.001 and 0.006 respectively.Scatter plot shows that with the increase of articular cartilage defects and bone marrow lesions,T2 values had an increasing trend.Conclusion This study shows that WOMAC pain,stiffness and joint dysfunction scores,age,gender and BMI were not the influence factor of T2 value.The higher grade of articular cartilage defects and bone marrow lesions,the higher the T2 value.T2mapping is a quantitative analysis method,which can effectively avoid the observer human error and is expected to provide more objective support for the articular cartilage defect score in KOA patients.