Clinical Study Of MRI Morphological And T1?T2?T2* Mapping Value For Normal Cartilage And Osteoarthritis Cartilage Lesions Of The Knee Joint

PART I The value of MRI in quantitative analysis of normal knee cartilage thickness and T1,T2 and T2Star valuesObjectiveTo investigate the difference of FS-PDWI?3D-DESS-WE?T1 Mapping?T2 Mapping and T2*Mapping for displaying normal knee cartilage,and the differences of the thickness,T1 Mapping?T2 Mapping and T2*Mapping value in different sex,different age group,different positions of normal knee cartilage.Materials and MethodsSixty healthy volunteer with the BMI between 18.5?23.9kg/m2 were collected,30 cases of male and female respectively.All of them were divided into two groups according of sex and three groups according of age.According to the age,there were 20 cases in each of the three groups of 20-30 years old,30-40 years old and 40-50 years old,with 10 cases in each age group for men and women.The cartilage thickness display scores,thickness and T1 Mapping,T2 Mapping and T2*Mapping values of the medial femoral condyle,lateral femoral condyle,femoral pulley,medial tibial condyle,lateral tibial condyle and patella of the knee joint were measured respectively.ResultsThe cartilage display score of plain scan sequence was superior to that of functional imaging Mapping sequence,and the display effect of 3d-dess-WE sequence was the best,with an average score of 3.40,followed by T1 Mapping sequence;T2Mapping and T2*Mapping were best in showing chondrogenic startification.The cartilage thickness of patella,femoral trochlear and medial femoral condyle of male knee joint was greater than that of female knee joint.Cartilage thickness in the trochlear region of the knee femur in the group aged 20-30 years was greater than that in the group aged 40-50 years,and there was no difference in cartilage thickness between other age groups.The T1Mapping values of male and female epicondyles were lower than those of female.There was no difference in T2Mapping and T2*Mapping values of cartilage in different genders,and the T2Mapping and T2*Mapping values of cartilage in the trochlear part of femur were significantly higher than those in other parts.The T1Mapping value of the 20-30 year-old group of femoral trochlear region was higher than that of the 30-40 year-old group,while the T1Mapping value of the 20-30 year-old group of femoral epicondylar region was lower than that of the 30-40 year-old group.The T2Mapping Value of cartilage in trochlear region of femur was the highest,and there were no differences in T2Mapping value of cartilage in different age groups.The T2*Mapping Value of the trochlear cartilage in the femur was the highest,and the T2*Mapping value in the 20-30 year-old group was higher than that in the 30-40 year-old group.ConclusionMagnetic resonance can display cartilage well,and the 3d-dess-WE sequence is optimal.There are differences in the morphology and biochemical quantitative values of knee normal cartilage in different positions,sex and ages.PART ? The diagnostic value of morphological and T1?T2?T2*Mapping technology for osteoarthritis(OA)cartilage lesion of knee jointObjectiveTo investigate the distribution of different grades of cartilage injury according to arthroscopy,and the differences in the display and biochemical measurements of the 3.0t MR1 examination sequences including FS-PDWI,3D-DESS-WE,T1 Mapping,T2 Mapping and T2*Mapping.Materials and MethodsSeventy-three knee joints with arthroscopy results and full MRI date(including conventional scan PDWI-FS,3d-DESS-WE,T1-Mapping,T2-Mapping,T2*-Mapping)have 213 cartilage lesions including 62 leisions with grade ?,51 grade ?,58 grade ? and 42 grade ?were collected.The arthroscopic results were used as the standard to compare the distribution of different levels of cartilage damage and to analyze the accuracy,sensitivity and specificity of PDWI,3D-DESS-WE,T1 mapping,T2mapping and T2*mapping for diagnosis of different grade cartilage lesions,and compare the differences of T1 mapping,T2 mapping,T2*mapping color graph and measured values between different levels of cartilage injury.The key is observing the diagnostic value of T2*mapping sequence on cartilage injury to be different from that of T1 mapping and T2mapping.ResultsLevel ? and level ? knee cartilage injuries are more likely to occur in the articular surface corresponding to patella and femoral pulley under arthroscopy,while level III and IV injuries,in addition to involving patella and femoral pulley,gradually develop to the medial and lateral articular surface cartilage,and the femoral epicondyle and tibial epicondyle are more vulnerable than the femoral epicondyle and the tibial epicondyle.The Kappa consistency test value for the diagnosis of cartilage injury and arthroscopy results was the highest in the 3d-dess-WE sequence(0.736),followed by the T2*Mapping sequence(0.663).The diagnostic accuracy of the two for different grades of cartilage injury was:grade I 80.0%,69.4%,grade ? 74.5%,64.7%,grade? 82.8%,72.4%,grade IV 95.2%,95.2%,respectively.T2Mapping and T2*Mapping were more valuable than TIMapping in the diagnosis of cartilage injury at different levels under arthroscopy.The added value of grade ? and ? injuries was greater,while that of grade ? injuries was decreased.The overall diagnostic accuracy was highest in the 3d-dess-WE sequence(79.8%),the sensitivity was highest in the T2*Mapping(93.9%),and the specificity was highest in the 3d-dess-WE sequence(85.9%).The combined sensitivity and specificity were significantly improved.ConclusionThe distribution characteristics and biochemical changes of different grades of cartilage injury in knee joint were different.The value of 3d-dess-WE sequence was the highest for diplaying the different grades of cartalige injury,but the sensitivity of T2*Mapping was the highest.The combined application of 3d-dess and T2*Mapping can significantly improve the diagnosis of OA cartilage lesions.