摘要
目的：探讨 MRI对前置胎盘和胎盘前置状态及伴发的胎盘植入的诊断价值。方法：搜集本院25例前置胎盘和胎盘前置状态孕妇的临床及影像学资料，年龄21-43岁，平均（29．4±6．2）岁，孕龄21～38周，平均（32．9±4．0）周，25例均行产前 MRI及超声（US）检查，以病理或分娩时临床诊断为金标准，对比分析两种检查的诊断价值。结果：25例前置胎盘和胎盘前置状态孕妇中，中央性19例，部分性3例，边缘性3例，MRI与US分别正确诊断20例、18例，两者对前置胎盘的诊断及分型差异无统计学意义（P＞0．05）。MRI诊断前置胎盘伴发胎盘植入敏感度71．4％，特异度72．7％，阳性预测值76．9％，阴性预测值66．7％；US诊断伴发胎盘植入敏感度66．7％，特异度69．2％，阳性预测值66．7％，阴性预测值69．2％。胎盘植入的 MRI表现主要有子宫底蜕膜信号缺失，子宫肌层局部变薄，胎盘与子宫交界面可见结节样改变，胎盘信号不均匀，在T2WI上胎盘内可见低信号带，胎盘与膀胱之间组织间隙减小或消失等。结论：MRI 和 US 对前置胎盘或前置状态伴发胎盘植入有重要价值，两者可相互补充。
Objective：To assess the value of MRI in the diagnosis of placenta previa as well as accompanying placenta accreta.Methods：The clinical and imaging materials of 25 pregnant patients with placenta previa were included in this study,the age ranged from 21-43y （mean,29.4±6.2y）,the gestational age of the fetuses at the time of MRI ranged from 21-38w （mean,32.9±4.0w）.All patients underwent MR and ultrasonography （US）before delivery.Taking pathology and the final clinical diagnosis during delivery as gold standard,the value of these two imaging modalities were compared and analyzed.Results：Among the 25 pregnant women with placenta previa,there were central complete type （19 cases）,partial type （3 cases）and marginal type （3 cases）.MRI and US correctly diagnosed 20 cases and 18 cases respectively,with no significant statistic difference （P＆gt;0.05）.The sensitivity and specificity of MRI and US for accompanying placenta accreta was 71.4%,66.7% and 72.7%,69.2%,respectively;the negative predictive value （NPV）and positive predictive value （PPV） was 76.9%,66.7% and 66.7%,69.2%,respectively.On MRI,the placenta accreta demonstrated partial loss of deciduum, focal thinness or absence of myometrium,nodular interface between placenta and uterus,heterogeneous signal intensities within placenta,bands of hypo-intensities within placenta on T2 WI,loss or diminish of the interspace between placenta and bladder.Conclusion：MRI and US play an important role in the diagnosis of placenta previa and accompanying placenta accreta,they are complementary.
出处
《放射学实践》
2014年第7期827-830,共4页
Radiologic Practice
关键词
前置胎盘
侵入性胎盘
磁共振成像
超声检查
Placenta previa
Placenta accreta
Magnetic resonance imaging
Ultrasonography
