MRI Of Articular Cartilage Degeneration And Correlation With Pathology

Objective:To explore the MRI value in diagnosing articular cartilage degeneration of knee joint by comparing T2 value, T2 Mapping,3D FS-SPGR and FS FSE PDWI appearances of tibial plateau cartilage degeneration with pathologic results.Materials and Methods:Twenty patients (31 knee joints) with total knee arthroplasty underwent MRI including T2 Mapping (T2 relaxation time),3D FS-SPGR and FS FSE PDWI. One hundred and two cartilage subregions (specimens) in 20 knee tibial plateaus were obtained.Using Collins pathological grade as a standard, we evaluated the ability of T2 value and T2 Mapping in displaying cartilage degeneration. The sensitivity, specificity, correct diagnosis index, and reliability of 3D FS-SPGR and FS FSE PDWI sequence to diagnose cartilage degeneration were assessed, and their advantages and disadvantages were compared.Results:(1) Overall, T2 value significantly increased with the severity of cartilage degeneration. The T2 value of gradeⅡwas slightly lower than that of gradeⅠ,but there was no significant difference between the two. There existed significant difference between the T2 value of gradeⅢand that of grade (0-11). The T2 value of grade I and that of grade 0 was significantly different. (2) Using Collins pathological classification as the standard, the sensitivity, specificity and correct diagnosis index of 3D FS-SPGR sequence and FS FSE PDWI sequence were 87.8% vs 55.6%,75.0% vs 83.3%,62.8% vs 38.9%, and the kappa value was 0.404 vs 0.158 respectively. (3) The sensitivity, reliability, and correct diagnosis index of 3D FS-SPGR in displaying cartilage degeneration were significantly higher than FS FSE PDWI, but the specificity was slightly lower than FS FSE PDWIConclusions:MRI of 3.0T can accurately display cartilage degeneration.①The T2 value of the articular cartilage had a high correlation with cartilage degeneration degree. T2 values significantly increased with the cartilage degeneration aggravating. It's a sensitive method to detectd early cartilage degeneration.②T2 Mapping can not distinguish the signal changes among the different degree of cartilage degeneration. Reduceing the threshold of T2 Mapping may help distinguish different degree of cartilage degeneration, Needed further study.③3D FS-SPGR was superior to FS FSE PDWI in the sensitivity, reliability, and correct diagnosis index in displayed cartilage degeneration, as a cartilage specificity sequence should added OA patient MRI sequence.