应用T2 mapping成像评价马拉松前后膝关节软骨短中期改变

Assessment of short-term and mid-term changes of knee cartilage before and after marathon using T2 mapping imaging

目的应用T2 mapping成像评价非专业长跑者马拉松前后膝关节软骨短中期改变。方法招募12名非专业马拉松运动员,其中男5名、女7名;年龄21.0~37.0岁,平均(27.5±5.2)岁;体质量指数(BMI)17.6~27.2 kg/m^2,平均(21.9±2.5)kg/m^2。入组受试者平均每周跑步3次以上,每次运动时间约30 min。参加马拉松赛的健康志愿者,24个膝关节在赛前1周、赛后12 h内及2个月时行3.0 T MR扫描。应用T2 mapping成像测量膝关节股骨内髁(MFC)、股骨外髁(LFC)、胫骨内侧平台(MTP)、胫骨外侧平台(LTP)、髌骨(Patella)和滑车(Trochlea)各亚区域软骨的浅层(SZ)、深层(DZ)T2值。赛前与赛后软骨T2值比较选用配对t检验,软骨浅层与深层T2值比较选用独立样本t检验。结果T2 mapping成像示关节软骨浅层T2值在赛前、赛后12 h内及2个月随访时均高于深层,差异有统计学意义(t值分别为11.095、10.385、10.102,P均<0.01)。赛后12 h内关节软骨浅层T2值较赛前低,差异有统计学意义(t值为2.180,P<0.05);膝关节整体软骨深层T2值与赛前相比,差异无统计学意义(t值为1.832,P>0.05)。赛后12 h内除MTP-DZ外,余软骨T2值均呈降低趋势,其中MFC-DZ与赛前比较差异有统计学意义(t=2.110,P<0.05)。赛后2个月随访时,2名受试者失访,MTP-SZ、LTP-SZ、LTP-DZ、MFC-DZ、Patella-SZ、Patella-DZ、Trochlea-SZ、Trochlea-DZ亚区软骨T2值与赛前相比差异无统计学意义(t值分别为0.857、0.573、0.146、0.510、-0.594、-1.135、-0.812、-0.679,P值均>0.05),LFC-SZ和LFC-DZ与赛前相比差异有统计学意义(t值分别为2.378、3.147,P值<0.05)。结论T2 mapping成像T2值的变化可以反映马拉松长跑者关节软骨内组织结构的变化过程,在压力作用下,软骨浅层T2值的变化更为显著。膝关节软骨的T2值在跑后2个月可逐渐恢复到跑前水平。

Objective Assessment of short-term and mid-term changes of knee cartilage in non-professional long-distance runners before and after marathon using T2 mapping imaging. Methods Twenty-four knee joints of 12 healthy volunteers (5 males and 7 females) who participated in the marathon were examined by 3.0 T MRI one week before the race, within 12 hours after the race and two months after the race, respectively. The age ranged from 21.0 to 37.0 years. Athletes run more than three times a week, and each time was about 30 minutes. From T2 mapping we can obtain T2 value of 6 cartilage subregions of knee joint. Paired t-test was used to compare the T2 values of cartilage before and after the marathon. The comparison between the superficial and deep T2 values of cartilage was performed by independent sample t test. Results T2 mapping imaging showed that the T2 value of the superficial articular cartilage was higher than that of deep articular cartilage in pre-competition, within 12 hours after competition and 2 months follow-up, respectively (t=11.095, 10.385 and 10.102, P<0.01). The T2 value of superficial articular cartilage decreased after the competition compared with that of pre-competition (t=2.18,P<0.05), while the T2 value of deep articular cartilage showed no significant difference compared with that of pre-competition (t=1.832, P> 0.05). Except for the MTP-DZ, the T2 value of the remaining cartilage subregions showed a trend of decrease within 12 hours after the competition. There were significant differences in the subregion of MFC-DZ (t=2.110,P<0.05). At the follow-up of 2 months, cartilage T2 values of the MTP-SZ,LTP-SZ,LTP-DZ,MFC-DZ, Patella-SZ, Patella-DZ, Trochlea-SZ, Trochlea-DZ subregions showed a trend of recovery, and there was no significant difference compared with pre-competition (t=0.857,0.573, 0.146, 0.510,-0.594,-1.135,-0.812,-0.679;P>0.05). The T2 values of the LFC-SZ and LFC-DZ were lower than those before the race, with statistical significance (t=2.378, 3.147,P<0.05). Conclusion T2 value could reflect the change process of articular cartilage tissue composition in marathon runners from T2 mapping imaging. Under stress, the changes of superficial T2 value are more significant. The T2 value of knee cartilage can gradually recover to the pre-run level 2 months after running.