T2* Mapping Technology Assesses The Impact Of Half Marathon On Knee Cartilage

Objective:To study the effect of half-marathon exercise on knee cartilage of non-professional marathon runners using quantitative T2*mapping technique.Methods:Twenty non-professional marathon runners performed a 1.5T MRI scan of the right knee joint before the half marathon,within 3 hours after the run,and one week after the run.Scan sequences include sagittal T1WI,PDWI,3D-DESS,T2*mapping sequences.Apply the Mapit post-processing tool to generate the T2*mapping pseudo-color map,and use the Fusion tool to fuse the 3D-DESS image with the T2*mapping pseudo-color map to obtain the fused image.Cartilage is divided into the following six parts:Patella cartilage?PC?,tochlea cartilage?TC?,medial tibiofemoral cartilage?MTC?,medial femoral cartilage?MFC?,Lateral tibial cartilage?LTC?,lateral femoral cartilage?LFC?.The medial and lateral cartilage of the tibial plateau and the lateral and lateral cartilage of the femoral condyle are subdivided into three parts:the anterior,middle and posterior;each cartilage is divided into a deep cartilage area and a shallow cartilage area according to its thickness.The thickest layer of cartilage in each region and the two layers before and after were selected to manually delineate the region of interest?ROI?,and the average of the three was recorded as the T2*value of the corresponding regional cartilage.One-way ANOVA was used to test the changes of T2*value of knee joint cartilage before running?t₀?,3h after running?t₁?and one week after running?t₂?.The average number of samples in each group was compared and analyzed by LSD method.Results:All non-professional marathon runners did not find positive cartilage lesions on conventional T1WI,PDWI and 3D-DESS before and after running and one week after running.The difference in the overall mean T2*value of the superficial region of the knee cartilage before running?t₀?,3h after running?t₁?and one week after running?t₂?was statistically significant.There was no statistical difference in the overall mean T2*value of the deep cartilage area.Learning meaning.Compared with before running,the average mean T2*value of the superficial layer of knee articular cartilage measured 3 h after running decreased significantly,the difference was statistically significant?P<0.05?,while the mean T2*value of cartilage deep layer was not statistically significant.The T2*values of the medial tibial plateau cartilage,the medial femoral condyle cartilage,the medial tibial plateau cartilage,the medial femoral condyle cartilage,the tibial cartilage and the trachoma cartilage were significantly decreased,the difference was statistically significant?P<0.05?.The posterior part of the medial tibial plateau cartilage,the posterior part of the medial femoral condyle cartilage,the tibial cartilage and the shallow layer of the trochlear cartilage were observed?P<0.01?.After a week of running,only the T2*value of the superficial temporal cartilage articular cartilage was significantly increased compared with that after running.The difference was statistically significant.Although the T2*values of other cartilage areas increased,the difference was not statistically significant;all cartilage areas The T2*value was not statistically different from before running.Conclusion:After a half marathon,the changes in knee cartilage composition of non-professional marathon runners are reversible and there is no permanent damage to the cartilage matrix.In the absence of positive findings in conventional magnetic resonance imaging,T2*mapping quantitative magnetic resonance imaging can objectively show changes in biochemical composition of articular cartilage during exercise,and can provide imaging evidence for cartilage changes in marathon.