MRI定量评估胎儿股骨发育的价值

Quantitative evaluation of fetal femur development by 3.0T magnetic resonance imaging

目的探讨3.0T MRI定量评估胎儿股骨发育的价值。方法选取并分析67例胎儿骨骼发育正常、胎龄(GA)24~39周的单胎妊娠的胎儿MRI资料,在单次激发快速自旋回波(SSFSE)序列图像测量胎儿股骨的二维径线(股骨干长度、股骨近端骨骺软骨横径、前后径和高径,股骨远端骨骺软骨横径、前后径和高径),观察股骨远端次级骨化中心的出现时间。应用直线相关分析检验胎儿股骨二维径线与GA的相关性。结果孕24~39周各胎龄相关性观察结果显示,胎儿股骨干长度(r=0.848)、股骨近端骨骺软骨横径(r=0.524)、前后径(r=0.572)、股骨远端骨骺软骨横径(r=0.509)、前后径(r=0.562)、高径(r=0.597)均与GA呈中~高度正相关(P均<0.001);股骨近端骨骺软骨高径(r=0.496)与GA呈低度正相关(P<0.001)。胎儿股骨远端次级骨化中心的出现时间为孕32周,孕34周以上为100%。结论3.0T MRI可较好地评估GA 24~39周胎儿股骨生长发育及解剖结构,股骨干长度是评价的最佳指标,可为评价胎儿股骨疾病及其发病机制提供参考依据。

Objective To investigate the value of 3.0T magnetic resonance imaging(MRI)in quantitative evaluation of fetal femur development.Methods The fetal MR data of 67 cases of singleton pregnancy with normal bone development at 24~39 gestational age(GA)were analyzed retrospectively.Two-dimensional radial line of fetal femur was measured on single shot fast spin echo(SSFSE)sequence images(Length of femoral shaft,transverse diameter,anteroposterior diameter and height diameter of epiphyseal cartilage of proximal femur and distal femur).We observed the appearance time of secondary ossification center of distal femur.Linear correlation analysis was used to test the correlation between the two-dimensional diameter of fetal femur and GA.Results The observation about the relevance of gestational age ranging from GA 24~39 weeks showed the length of femoral shaft of intrauterine fetus(r=0.848),transverse diameter of epiphyseal cartilage in proximal femur(r=0.524),anteroposterior diameter of epiphyseal cartilage in proximal femur(r=0.572),transverse diameter of epiphyseal cartilage of distal femur(r=0.509),anteroposterior diameter of epiphyseal cartilage in distal femur(r=0.562),height diameter of epiphyseal cartilage in distal femur(r=0.597)were positively correlated with GA(all P<0.001);There was a low positive correlation between the height diameter of epiphyseal cartilage in proximal femur(r=0.496)and GA(P<0.001).The secondary ossification center of distal femur appeared at 32 weeks of gestation,whose occurrence rate was 100%when it was over 34 weeks of gestation.Conclusion 3.0T MRI can better evaluate the growth,development and anatomical structure of fetal femur at 24~39 weeks of GA,and the length of femoral shaft is the best evaluation index,which can provide reference for the evaluation of fetal femur diseases and their pathogenesis.