MRI诊断胎儿脊柱脊髓畸形的价值和序列选择

The value and sequence selection of MRI in the diagnosis of spinal cord malformations in fetus

目的探讨胎儿脊柱脊髓畸形诊断中磁共振成像(MRI)的价值和序列选择。方法50例疑似脊柱脊髓畸形胎儿,均进行MRI检查、电子计算机断层扫描(CT)检查。比较两种检查方法的脊柱脊髓畸形类型检出情况;两种检查方法的辐射情况、不良反应发生情况;以手术病理检查结果为金标准,比较两种检查方法的诊断效能;分析MRI检查不同序列[真实稳态进动快速成像序列(Trufi)、半傅里叶采集单次激发快速自旋回波序列(Haste)、磁敏感加权成像(SWI)]显示胎儿不同脊柱脊髓病变的图像质量。结果MRI检查的脊髓空洞、脊髓纵裂、脊髓低位、椎体畸形、脊柱裂检出率分别为96.00%、94.00%、90.00%、88.00%、74.00%,均高于CT检查的64.00%、60.00%、52.00%、56.00%、46.00%,差异具有统计学意义(P<0.05)。MRI检查的辐射率2.00%、不良反应发生率4.00%均低于CT检查的16.00%、16.00%,差异具有统计学意义(P<0.05)。以手术病理检查结果为金标准,MRI检查的灵敏性93.48%、准确性92.00%均高于CT检查的78.26%、76.00%,差异具有统计学意义(P<0.05);两种检查方法的特异性、阳性预测值、阴性预测值比较,差异无统计学意义(P>0.05)。Haste、Trufi序列诊断胎儿脊髓与椎管内异常的图像质量佳,SWI诊断胎儿椎体畸形的图像质量佳。结论胎儿脊柱脊髓畸形诊断中MRI的价值较CT高,其中Haste、Trufi序列更适用于胎儿脊髓与椎管内异常的诊断,SWI更适用于胎儿椎体畸形的诊断。

Objective To discuss the value and sequence selection of magnetic resonance imaging(MRI)in the diagnosis of spinal cord malformations in fetus.Methods 50 fetuses with suspected spinal cord malformations were examined by MRI and computed tomography(CT).Comparison was made on the detection of spinal cord malformation types between the two examination methods,and the radiation exposure and the occurrence of adverse reactions between the two examination methods.The diagnostic efficacy of the two examination methods using surgical pathology findings as the gold standard.The image quality of different sequences[true fast imaging with steady-state free precession(Trufi),half-Fourier acquisition single-shot turbospinecho(Haste),susceptibility-weighted imaging(SWI)]of MRI examinations showing different spinal cord lesions in the fetus was analyzed.Results The detection rates of syringomyelia,diastematomyelia,low spinal cord,vertebral body deformity and spina bifida in MRI examination were 96.00%,94.00%,90.00%,88.00%and 74.00%,which were higher than 64.00%,60.00%,52.00%,56.00%and 46.00%in CT examination,and the differences were all statistically significant(P<0.05).The radiation rate of MRI examination was 2.00%and the incidence of adverse reactions was 4.00%,which were lower than 16.00%and 16.00%of CT examination,and the differences were all statistically significant(P<0.05).Taking surgical pathology findings as the gold standard,the sensitivity of MRI examination was 93.48%and the accuracy was 92.00%,which were higher than 78.26%and 76.00%of CT examination,and the differences were all statistically significant(P<0.05).There was no statistically significant difference in the specificity,positive predictive value and negative predictive value of the two inspection methods(P>0.05).Haste and Trufi sequences had good image quality for diagnosing fetal spinal cord and spinal canal abnormalities,and SWI had good image quality for diagnosing fetal vertebral malformations.Conclusion MRI is more valuable than CT in the diagnosis of spinal cord malformations in the fetus,where Haste and Trufi sequences are more suitable for the diagnosis of fetal spinal cord and spinal canal abnormalities,and SWI is more suitable for the diagnosis of fetal vertebral malformations.