Quantitative T2-Mapping and T2(⁎)-Mapping Evaluation of Changes in Cartilage Matrix after Acute Anterior Cruciate Ligament Rupture and the Correlation between the Results of Both Methods

OBJECTIVES: To quantitatively assess changes in cartilage matrix after acute anterior cruciate ligament (ACL) rupture using T2- and T2(⁎)-mapping and analyze the correlation between the results of both methods. METHODS: Twenty-three patients and 23 healthy controls were enrolled and underwent quantitative MRI examination. The knee cartilage was segmented into six compartments, including lateral femur (LF), lateral tibia (LT), medial femur (MF), medial tibia (MT), trochlea (Tr), and patella (Pa). T2 and T2(⁎) values were measured in full-thickness as well as superficial and deep layers of each cartilage compartment. Differences of T2 and T2(⁎) values between patients and controls were compared using unpaired Student's t-test, and the correlation between their reciprocals was analyzed using Pearson's correlation coefficient. RESULTS: ACL-ruptured patients showed higher T2 and T2(⁎) values in full-thickness and superficial layers of medial and lateral tibiofemoral joint. Meanwhile, patients exhibited higher T2(⁎) values in deep layers of lateral tibiofemoral joint. The elevated percentages of T2 and T2(⁎) value in superficial LT were most significant (20.738%, 17.525%). The reciprocal of T2(⁎) value was correlated with that of T2 value (r = 0.886, P < 0.001). CONCLUSION: The early degeneration could occur in various knee cartilage compartments after acute ACL rupture, especially in the superficial layer of LT. T2(⁎)-mapping might be more sensitive in detecting deep layer of cartilage than T2-mapping.