合成MRI在业余马拉松运动员膝关节监测中的初步研究

Monitoring changes of knee in amateur marathon athletes using synthetic MRI:a preliminary study

目的:探讨合成MRI对业余马拉松运动员参加全程马拉松赛前后膝关节结构和软骨改变定量检测的价值。方法:2019年10月至2020年1月间招募广东省珠海市业余马拉松爱好者26名。在全程马拉松运动前1周、运动后48 h内对其右膝关节进行扫描,扫描序列包含三维各向同性快速自旋回波质子密度加权(3D CUBE PD)序列和合成MRI序列,后者扫描后获得常规对比加权图像T_(1)WI、T_(2)WI、质子密度(PD)加权像、短时反转恢复序列(STIR)以及T_(1)、T_(2)、PD 3种定量图谱。以3D-CUBE-PD序列为参照,评估合成MRI对膝关节病变的检出情况。将膝关节软骨分为股骨内侧髁中央承重区(CMFC)、股骨内侧髁后部非承重区(PMFC)、股骨外侧髁中央承重区(CLFC)、股骨外侧髁后部非承重区(PLFC)、胫骨内侧平台(MTP)、胫骨外侧平台(LTP)、髌骨及滑车8个亚区,基于合成MRI,由2名医师对各软骨亚区分别独立测量其T_(1)、T_(2)、PD值。采用ICC评价观察者间测量数据的一致性,马拉松运动前后膝关节软骨T_(1)、T_(2)及PD值的比较采用Wilcoxon符号秩和检验。结果:2名医师对膝关节软骨的T_(1)、T_(2)及PD值测量的一致性好,ICC值分别为0.912、0.933及0.954。合成MRI序列可检出所有软骨损伤(3名)和关节积液(15名),9名半月板损伤者检出7名。膝关节软骨整体T_(1)、T_(2)及PD值在运动前均高于运动后,差异有统计学意义(P均<0.05),T_(1)值除髌骨和滑车软骨外,其他区域均有统计学意义,T_(2)值CMFC、LTP、MTP亚区差异有统计学意义(P均<0.05)。结论:合成MRI技术对膝关节结构病变有较好的显示能力,其定量参数T_(1)、T_(2)、PD值可有助于检测马拉松远动前后膝关节软骨的改变。

Objective To explore the value of synthetic MRI in quantitative monitoring of knee joint structural and cartilage changes of amateur marathon runners before and after the whole marathon.Methods Totally 26 amateur marathon enthusiasts from Zhuhai City,Guangdong Province were recruited from October 2019 to January 2020.The right knee joints were scanned 1 week before the race and within 48 h after the race.The scanning sequence included the three-dimensional proton density weighted image with isotropic(3D-CUBE-PD)sequence and synthetic MRI sequence.The conventional contrast weighted images T1WI,T2WI,proton density(PD)weighted imaging,short-T1 inversion recovery(STIR)and T1,T2,PD mapping were obtained by the latter scans.The 3D-CUBE-PD sequence was used as a reference to evaluate the detection of knee joint lesions.The knee articular cartilage was divided into 8 subregions:central medial femoral condyle(CMFC),posterior medial femoral condyle(PMFC),central lateral femoral condyle(CLFC),posterior lateral femoral condyle(PLFC),medial tibia plateau(MTP),lateral tibia plateau(LTP),patella and trochlear.Based on the synthetic MRI quantitative mapping,the T1,T2 and PD values of each cartilage subregion were measured independently by 2 radiologists.The ICC was used to evaluate the consistency of the measurement between observers.The T1,T2 and PD values of knee cartilage before and after marathon exercise were compared by Wilcoxon signed rank test.Results The 2 radiologists had good consistency in the measurement of T1,T2 and PD values of knee articular cartilage with the ICC values of 0.912,0.933 and 0.954,respectively.The synthetic MRI quantitative mapping sequence can detect all cartilage damage(n=3)and joint effusion(n=15),and 7 of 9 meniscus injuries were detected.The T1,T2 and PD values of the knee cartilage as a whole before the race were higher than those after race,and the differences were statistically significant(all P<0.05).The T1 values were statistically significant except patellar cartilage and trochlear cartilage,and T2 values were significantly different in the CMFC,LTP,MTP(P<0.05).Conclusion Synthetic MRI has a good display of knee joint structural lesions,and its quantitative parameters T1,T2 and PD can detect the changes of knee cartilage before and after marathon.