Conventional Mri Combined With T2* Mapping To Evaluate The Effect Of Half Marathon On Knee Meniscus Of Amateur Marathon Athletes

Objective: To observe the changes of MRI signal in knee meniscus of amateur marathon athletes before and after a single half marathon.The quantitative T2*mapping technique was used to dynamically observe the short-term effects of half marathon exercise on meniscus biochemical components.Methods: A total of 20 male amateur marathon runners with a total of 40 knee joints were recruited in this study.1.5TMRI examinations of both knee joints were performed at 1 week before half marathon(T0),3 hours after running(T1),3 days after running(T2)and 1 week after running(T3).MRI scan sequences included conventional sagittal T1 WI,sagittal and coronal FS-PDWI,and sagittal T2*mapping sequences.The knee meniscus is divided into medial anterior Angle of meniscus(MMA),medial posterior Angle of meniscus(MMP),medial body of meniscus(MMB),lateral anterior Angle of meniscus(LMA),lateral posterior Angle of meniscus(LMP),and lateral body of meniscus(LMB).The meniscal Stoller scale was used to evaluate the pre-half-marathon(T0)meniscus on conventional sagittal T1 WI,sagittal,and coronal FS-PDWI images,and changes in meniscus signal were observed during three follow-up visits.The original T2*mapping image was transferred to the workstation to automatically generate the T2*mapping pseudo color image,and the anatomical image was associated with the T2*mapping pseudo color image through the workstation.Select the anterior and posterior corners of the meniscus to display the maximum level measurement.Select the first level measurement on the body of the meniscus,which is connected with the front and rear parts of the meniscus,and manually outline the ROI to get the T2* value of the meniscus in the corresponding area.One-way analysis of variance(ANOVA)was used to test the changes of knee meniscus T2* values before(T0),3 hours(T1),3 days(T2)and 1 week(T3)after running,and LSD method was used to test and analyze the mean of multiple groups in pair.Results: Sixteen of the 20 male amateur marathoners completed full follow-up with a total of 30 knee joints(16 in the right knee and 14 in the left knee).All amateur marathoners had no meniscus tear(grade 3)in knee joint before running(t0).In 30 cases of knee meniscus,Grade 1 signal: 8 cases of MMA(26.7%),11 cases of MMP(36.7%),6 cases of LMA(20%),and 5 cases of LMP(16.7%).Grade 2 signal: 5 cases of MMP(16.7%),2 cases of MMB(6.7%)and 2 cases of LMP(6.7%),among which the incidence of MMP degeneration(grade 1 + grade 2 signal)was the highest(53.3%).Routine MRI meniscus signals did not change significantly during 3follow-up visits after a single half marathon.Compared with before running,T2*values in all areas of the meniscus increased at 3h and 3d after half marathon running,with statistical significance(P <0.05).Except for MMA,the meniscus region increased the most at 3d(t2)after running.After running,T2* value of medial meniscus increased significantly,posterior Angle(10.9%)> body(7.5%)BBB>terior horn(6.9%),posterior Angle of lateral meniscus(7.3%)BBB2 b>(5.7%)= anterior horn(5.7%);There was no significant difference in the T2* values of each region of the meniscus 1 week after running(t3)compared with that before running(t0)(P >0.05).Conclusion: There was no meniscus tear in the knee joint of the amateur marathon runners in this group,and the degeneration rate of the posterior horn of the medial meniscus was the highest.There was no significant change in the meniscus signal on conventional MRI after a single half marathon.After half marathon,the T2*value of meniscus in each region increased firstly and then decreased,and recovered to the level before half marathon one week later,indicating that the change of meniscus composition after half marathon was reversible.The T2* mapping technique was able to assess the changes in the tissue composition of the meniscus during exercise.