Application Of T2 Mapping Sequence In The Diagnosis Of Meniscus Injury Of The Knee Joint

Objective:To explore the application value of T2 mapping in the diagnosis of meniscus injury in the knee joint.Methods:50 cases of patients had accepted the knee joint MRI examination and 4 patients accepted arthroscopic surgery,which included routine MRI sequences and T2 mapping sequences.All patients were divided into 3 groups according to the MRI features of the meniscus,the normal meniscus group,the degenerated meniscus group,the torn meniscus group.The morphological differences of T2 mapping and PDWI/T2WI were analyzed among three groups.The difference of the T2 value of the meniscus among three groups was evaluated by the multiple independent samples of variance test.ROC curve of T2 value between different groups was established to find the optimal diagnostic threshold for the actual diagnosis.Results:There were 100 meniscus in 50 patients..Among them,there were 38 meniscus in the normal group,34 meniscus in the generation group and 28 meniscus in the torn group.The mean value of T2 value in the normal group,the degeneration group and the torn group was 17.81 + 1.75?23.14 +2.25?31.17 + 5.54 respectively.The difference of the mean value of T2 value among three groups was statistically significant,P<0.05.It was suggested that the area under the curve of ROC curve of the T2 value between the normal and degeneration group was 0.959 and 20.5 of T2 value is the optimal diagnostic threshold.The sensitivity and specificity of the optimal diagnostic threshold was respectively 85%and 94.7%.The area under the ROC curve of degeneration and torn group was 0.92 and the optimal diagnostic threshold of the T2 value was 25.5 between the degeneration and torn group,the sensitivity and the specificity of which was 89.3 and 91.2%,respectively.There were respectively 38,24 and 7 meniscuses with a regular shape on PWI/T2WI among the normal meniscus group,the degenerated meniscus group and the torn meniscus group,while there were 36,15 and 4 regular meniscuses on T2 mapping image among three groups separately.The number of the sharp edge of meniscus on PWI/T2WI were 38 in the normal group,29 in the degeneration group and 10 in the torn group respectively,among which,only 24 in the normal group,7 in the degeneration group and 5 in the torn group were observed on T2 mapping image.The demonstration of the rim of 8 meniscus under arthroscopic survey was consistent with the result on T2 mapping image.Conclusion:T2 mapping sequence could be used to reveal the meniscus injury,which is more sensitively on the observation of the rim of meniscus than the conventional MRI sequences.T2 value is helpful in the grading and quantitative diagnosis of meniscus injury.