基于MRI T_(2)弛豫时间参数图的业余马拉松运动员比赛前后膝关节周围肌肉T_(2)值变化特征分析

Analysis of the characteristics of MRI T_(2) value changes of the muscles around the knee joint before and after the race in amateur marathon runners based on T_(2) mapping

目的基于MRI T_(2)弛豫时间参数图分析业余马拉松运动员膝关节周围肌肉T_(2)值变化特征。方法招募业余马拉松运动员12名为马拉松组,其中男5名,女7名,年龄21~37(27.5±5.4)岁。于马拉松赛前1周、赛后12 h及赛后2个月进行双膝关节MRI检查;招募健康志愿者15名为对照组,其中男5名,女10名,年龄24~27(24.9±1.0)岁,进行双膝MRI检查。应用T_(2)弛豫时间参数图成像序列在后处理平台测量缝匠肌、股内侧肌、股二头肌、半膜肌、腓肠肌内侧头及腓肠肌外侧头的T_(2)值,分析马拉松组赛前与赛后12 h内和赛后2个月及马拉松组赛前与对照组之间各肌肉T_(2)值的差异。结果所有受试者检查期间均未出现膝关节疼痛。常规MRI检查显示,膝关节周围肌肉形态及信号均未见明显异常。与赛前相比,马拉松赛后12 h马拉松组中半膜肌[(34.3±2.8)ms比(35.5±2.5)ms,P=0.008]、腓肠肌内侧头[(34.1±3.4)ms比(37.7±3.1)ms,P<0.001]、腓肠肌外侧头[(35.2±2.9)ms比(37.2±3.9)ms,P=0.011]T_(2)值明显升高;余肌肉T_(2)值变化差异无统计学意义(均P>0.05)。赛后2个月随访,半膜肌T_(2)值水平仍高于跑前[(34.3±2.8)ms比(35.4±2.5)ms,P=0.043];腓肠肌内侧头与腓肠肌外侧头T_(2)值与跑前相比差异无统计学意义(P>0.05)。马拉松组腓肠肌外侧头的T_(2)值低于对照组[(35.3±3.0)ms比(38.5±4.1)ms,P=0.007];马拉松组余肌肉T_(2)值与对照组相比差异无统计学意义(P>0.05)。结论马拉松赛后膝关节周围肌肉的T_(2)值改变是可逆的。T_(2)弛豫时间参数图成像序列可在一定程度上间接反映膝关节周围肌肉微观结构的改变。

Objective To evaluate the characteristics of MRI T_(2) value changes of muscles around the knee joint in amateur marathon athletes based on T_(2) mapping.Methods A total of 12 amateur marathon runners(5 males and 7 females)were recruited as the marathon group,aged from 21 to 37(27.5±5.4)years.MRI examination of bilateral knee joint was performed one week before the race,within 12 hours after the race and two months after the race,respectively.Fifteen healthy volunteers(5 males and 10 females)were recruited as the control group,aged from 24 to 27(24.9±1.0)years,and underwent MRI examination of both knee joints.The T_(2) mapping imaging sequence was used to measure the T_(2) values of the sartorius,vastus medialis,biceps femoris,semimembranosus,medial head of gastrocnemius and lateral gastrocnemius head on the post‑processing platform,and analyzed the marathon group before and after the race.The differences in the T_(2) value of each muscle of the marathon group before and after the race within 12 hours,before and 2 months after the race,and between the control group and the marathon group before the marathon were analyzed.Results All subjects had not knee joint pain during the examination.Routine MRI examination showed that there was no obvious abnormality in the shape and signal of the muscles around the knee joint.The T_(2) value of the semimembranosus[(34.3±2.8)ms vs(35.5±2.5)ms,P=0.008],medial head of gastrocnemius[(34.1±3.4)ms vs(37.7±3.1)ms,P<0.001]and lateral head of gastrocnemius[(35.2±2.9)ms vs(37.2±3.9)ms,P=0.011]increased after the competition compared with that of pre‑competition in the marathon group,while the T_(2) value of the remaining muscles showed no significant difference compared with that of pre‑competition(P>0.05).At the follow‑up of 2 months,the T_(2) value of semimembranosus remains higher than before the marathon[(34.3±2.8)ms vs(35.4±2.5)ms,P=0.043],and the T_(2) value of the medial head of the gastrocnemius and lateral head of gastrocnemius showed no statistically difference compared with pre‑competition(P>0.05).Compared with the control group,the T_(2) value of the lateral head of the gastrocnemius in the marathon group was decreased[(35.3±3.0)ms vs(38.5±4.1)ms,P=0.007].There was no significant difference in the T_(2) value of the remaining muscles in the marathon group(P>0.05).Conclusions After the marathon,the changes in the T_(2) value of the muscles around the knee joint is reversible.T_(2) mapping imaging sequence can indirectly reflect the changes of skeletal muscle microstructure to a certain extent.