Résumé
Objective@#To study the effects of half marathon loading on the T2* mapping assessment of knee joint cartilage.@*Methods@#Twenty male amateur marathon runners with more than three years of running age were enrolled. The T1WI, PDWI, 3D-DESS, and T2* mapping were performed on right knee joint before and after the half marathon within 3h and after a period of approximately 1 week. Cartilage was divided into 6 regions: medial and lateral femoral cartilage, medial and lateral tibial cartilage and patella and trochlea cartilage. Femoral cartilage was partitioned into central weight-bearing regions, posterior cartilage nonweight-bearing regions with the posterior boundary of the meniscus as the dividing mark. All cartilage was further divided into deep and superficial layers according to the thickness 1/2, and the ROI was delineated to obtain the T2* value of the corresponding area. One-way repeated measures analysis was performed to test the difference of T2* values pre- and post-marathon. LSD tests were used to estimate the different influences of physiological activities on each articular cartilage area.@*Results@#All cartilage areas of the knee joint did not show cartilage injury during the examination. The differences in the global T2* values of the superficial layers of the knee cartilage before and after the half-marathon marathon were statistically significant (t=5.145, P<0.05), but the global T2* value of the deep region were not (t=1.864, P>0.05). After a week, the T2* values of all cartilage areas were not statistically different from those before running (t=1.062, 0.309; P>0.05).@*Conclusion@#After a single half marathon, the changes of knee cartilage composition in male amateur marathon runners are reversible. In the absence of positive findings in conventional MRI, T2* mapping can indirectly reflect changes in biochemical composition of the articular cartilage during exercise.
Résumé
Objective To study the effects of half marathon loading on the T2* mapping assessment of knee joint cartilage. Methods Twenty male amateur marathon runners with more than three years of running age were enrolled. The T1WI, PDWI, 3D?DESS, and T2*mapping were performed on right knee joint before and after the half marathon within 3h and after a period of approximately 1 week. Cartilage was divided into 6 regions: medial and lateral femoral cartilage, medial and lateral tibial cartilage and patella and trochlea cartilage. Femoral cartilage was partitioned into central weight?bearing regions, posterior cartilage nonweight?bearing regions with the posterior boundary of the meniscus as the dividing mark. All cartilage was further divided into deep and superficial layers according to the thickness 1/2, and the ROI was delineated to obtain the T2* value of the corresponding area. One?way repeated measures analysis was performed to test the difference of T2*values pre?and post?marathon. LSD tests were used to estimate the different influences of physiological activities on each articular cartilage area. Results All cartilage areas of the knee joint did not show cartilage injury during the examination. The differences in the global T2*values of the superficial layers of the knee cartilage before and after the half?marathon marathon were statistically significant (t=5.145, P<0.05), but the global T2*value of the deep region were not (t=1.864, P>0.05). After a week, the T2* values of all cartilage areas were not statistically different from those before running (t=1.062, 0.309; P>0.05). Conclusion After a single half marathon, the changes of knee cartilage composition in male amateur marathon runners are reversible. In the absence of positive findings in conventional MRI, T2* mapping can indirectly reflect changes in biochemical composition of the articular cartilage during exercise.