目的评估 MRI 对产前胎盘植入的诊断价值，初步探讨胎盘植入 MRI 征象与胎盘植入类型的关系。资料与方法收集54例具有胎盘植入高危因素的孕产妇的产前临床资料及产后手术病理资料，并行常规盆腔 MRI 检查，扫描序列主要包括T2WI 快速自旋回波序列及平衡式快速场回波序列横断位、矢状位及冠状位，观察MRI 征象，并选取胎盘内在3个方位均表现为低信号的区域测量面积，分析 T2WI上胎盘低信号带面积与胎盘植入类型的相关性。结果54例患者的胎盘植入发生率为64.8%（35/54）。主要 MRI 征象：T2WI 呈低信号带37例（68.5%），胎盘内信号不均匀31例（57.4%）；胎盘穿透的主要 MRI 征象为膀胱“帐篷征”（75.0%，6/8）。胎盘植入类型与 T2WI 低信号带面积呈正相关（r=0.454，P<0.05）。结论胎盘植入的典型间接征象为 T2WI 上低信号带及胎盘内信号不均匀，且 T2WI 上胎盘内低信号带面积越大，胎盘植入深度越深。具有胎盘植入高危因素的孕产妇产前需进行影像学评估，特别是 MRI 检查，以提高疾病检出率。%Purpose To discuss the value of MRI in the diagnosis of placenta implantation abnormality, and to explore preliminarily the relationship between MRI signs and types of placenta implantation abnormality. Materials and Methods The clinical preoperative data and postnatal pathological findings of 54 women at high risk of placenta accreta were collected. All the patients undertook the conventional pelvic MRI examination. The scanning sequences mainly included: sagittal, coronal and axial T2-weighted imaging-turbo spin echo, balance fast field echo. The MRI images were observed and the areas which showed low signal in all the three directions on T2WI were measured. Then the correlation between the areas of low signal on T2WI in placental and the types of placenta implantation abnormality was analyzed. Results The incidence of placenta implantation abnormality was 64.8% in our research (35/54). The main MRI signs were low signal on T2WI (68.5%, 37/54) and heterogeneous signal in placenta (57.4%, 31/54); the main sign of placenta percreta was "tenting" bladder (75.0%, 6/8). The types of placenta implantation abnormality were positively correlated with the areas of low signal on T2WI (r=0.454, P<0.05). Conclusion Pregnant women at risk of placenta accreta should be evaluated with imaging examinations, particularly with MRI scanning, to improve disease detection rate. The typical indirect signs of placenta implantation abnormality are low signal on T2WI and heterogeneous signal in placenta. The larger size of low signal area on T2WI in placenta, the deeper implantation of placenta.
展开▼
