集成磁共振成像在业余马拉松运动员膝关节周围肌肉监测中的初步研究

Monitoring changes of the muscles around the knee joint in amateur marathon athletes using synthetic magnetic resonance imaging:A preliminary study

目的探讨集成磁共振成像(synthetic magnetic resonance imaging,SyMRI)技术对业余马拉松运动员参加马拉松赛前后膝关节周围肌肉定量检测的价值。材料与方法前瞻性招募业余马拉松运动员24例(48侧膝关节),其中男21名,女3名;年龄24~50(40±6)岁。所有受试者均采用GE SIGNA Pioneer 3.0 T MRI进行检查。于马拉松赛前1周、赛后48 h及赛后1个月分别进行双膝关节SyMRI序列检查;扫描后获得常规对比加权图像以及T1、T2、质子密度(proton density,PD)3种定量图谱。应用ITK-SNAP软件后处理平台,在膝关节矢状位图像测量半膜肌、股二头肌、股外侧肌、股内侧肌、腓肠肌内侧头及腓肠肌外侧头、腘肌、胫骨前肌的T1、T2、PD值,分析赛前与赛后48 h内、赛后1个月各肌肉T1、T2、PD值的变化情况。结果所有受试者检查期间膝关节周围肌肉形态及信号均未见明显异常。2名放射科医师对膝关节周围肌肉的T1、T2及PD值测量的结果一致性好,ICC值分别为0.801、0.909和0.921。与赛前相比,受试者大多数肌肉亚区在马拉松赛后48 h的T1、T2、PD值升高,赛后休息1个月后下降;半膜肌、股二头肌、股外侧肌、股内侧肌、腓肠肌内侧头及腓肠肌外侧头的T2值变化差异有统计学意义(P<0.05),股内侧肌PD值的变化差异有统计学意义(P<0.05)。结论SyMRI序列的定量参数值可有助于检测马拉松运动前后膝关节肌肉的动态变化。

Objective:To investigate the value of synthetic MRI(SyMRI)sequences for quantitative detection of the muscles around the knee joints before and after amateur marathon runners participated in a marathon.Materials and Methods:Twenty-four amateur marathon runners(48 knees),21 males and 3 females,aged 24 to 50(40±6)years,were prospectively recruited.All subjects were examined with GE SIGNA Pioneer 3.0 T MRI.SyMRI sequences of both knees were performed 1 week before the marathon,48 hours after the marathon,and 1 month after the marathon.Conventional contrast-weighted images as well as 3 quantitative profiles of T1,T2,and proton density(PD)were obtained after scanning.ITK-SNAP software was applied in the post-processing platform to measure the T1,T2,and PD values of the semimembranosus,biceps femoris,lateral femoris,medial femoris,medial head of the gastrocnemius,and lateral head of gastrocnemius,popliteus,and tibialis anterior muscles in sagittal images of the knee joint.The differences in T1,T2,and PD values of each muscle were analyzed before and 48 hours after the race and 1 month after the race.Results:All subjects showed no significant abnormalities in muscle morphology or signal around the knee during the examination(P>0.05).The values of T1,T2 and PD of the muscles around the knee joint measured by two radiologists were good consistent,with ICC values of 0.801,0.909 and 0.921,respectively.Most muscle subregions had elevated T1,T2,and PD values 48 hours after the marathon compared to pre-race,and decreased after 1 month of post-race rest.There were statistically significant changes in T2 values for semimembranosus,biceps femoris,lateral femoris,medial femoris,medial head of the gastrocnemius,and lateral head of gastrocnemius(P<0.05),and statistically significant changes in PD values for medial femoris(P<0.05).Conclusions:The quantitative parameter values of SyMRI sequences can be useful for detecting dynamic changes in the knee muscles before and after marathon exercise.