探讨不同超声图像特征在胎盘植入诊断中的应用价值。

回顾性分析2016年4月至2017年7月中南大学湘雅医院分娩的112例产前超声诊断为前置胎盘患者的超声声像图。所有患者均经手术病理确诊。以手术病理结果作为金标准，计算各超声图像特征诊断胎盘植入的敏感度、特异度、阳性预测值、阴性预测值；以手术结果作为金标准，计算各超声图像特征预测胎盘植入患者产后子宫切除的敏感度、特异度、阳性预测值、阴性预测值。

本组112例产前超声检查诊断为前置胎盘患者，手术病理结果确诊为胎盘植入71例，非胎盘植入41例，产前超声诊断准确72例，诊断准确率为64.1%。以手术病理结果作为金标准，胎盘后间隙消失、肌层菲薄或消失、胎盘内虫蚀样腔隙、胎盘后方或胎盘与膀胱间血流信号丰富诊断胎盘植入的敏感度分别为83.10%、64.79%、43.66%、64.79%，特异度分别为29.27%、73.17%、87.80%、58.54%、阳性预测值分别为67.05%、80.70%、86.11%、73.02%，阴性预测值分别为50.00%、54.55%、47.37%、48.98%。胎盘后间隙消失诊断胎盘植入的敏感度最高，特异度最低；而胎盘内虫蚀样腔隙诊断胎盘植入的特异度最高。以手术结果作为金标准，胎盘后间隙消失、肌层菲薄或消失、胎盘内虫蚀样腔隙、胎盘后方或胎盘与膀胱间血流信号丰富预测胎盘植入患者产后子宫切除的敏感度分别为100%、77.78%、61.11%、83.33%，特异度分别为25.53%、54.26%、73.40%、48.94%，阳性预测值分别为20.45%、24.54%、30.56%、23.81%，阴性预测值分别为100%、92.73%、90.79%、93.88%。胎盘后间隙消失预测胎盘植入患者产后子宫切除的敏感度较高，但是特异度低；胎盘内虫蚀样腔隙预测胎盘植入患者产后子宫切除的敏感度、特异度均较高。

超声检查在产前诊断胎盘植入有重要的价值，其中胎盘后间隙消失敏感度高诊断胎盘植入特异度低，而胎盘内虫蚀样腔隙诊断胎盘植入特异度高，且与前置胎盘患者妊娠结局有一定关联。对于有剖宫产史的前置胎盘患者应行规范化胎盘超声检查，提高胎盘植入的检出率。

To investigate the value of various ultrasound parameters in the diagnosis of placenta accreta.

To retrospectively analyze the sonographic images of 112 patients with prental diagnosis of placenta previa at Xiangya Hospital of Central South University between April 2016 and July 2017. All patients were confirmed by surgery pathology. Pathology was as golden standard for diagnosis, and the sensitivitity, specificity, positive predictive value and negative predictive value of each ultrasound parameter in the prenatal dianosis of placenata accreta and the predicting postpartum hysterectomy of patients with placenta accreta were calculated.

Of 112 patients with placenta previa, 71 cases were confirmed with placenta accreta by histology, 41 cases without placenta accrete, accurate prenatal ultrasound diagnosis is 72 cases, the accuracy is 64.1%. Ultrasonic parameters assessed included loss of retroplacental clear zone, smallest myometrial thickness, presence of ″moth-eaten″ lacunar spaces, and sub-placental or the posterior wall of the bladder hypervascularity. The sensitivity (specificity) of diagnosis of placenta accreta was 83.10% (29.27%), 64.79% (73.17%), 43.66% (87.80%), 64.79% (58.54%), respectively, the positive predictive value (negative predictive value) was 67.05% (50.00%), 80.70% (54.55%), 86.11% (47.37%), 73.02% (48.98%), respectively, the loss of retroplacetal clear zone has high sensitivity and low specificity in the prenatal diagnosis of placenata accreta, the presence of ″moth-eaten″ lacunar spaces has the highest specificity. The sensitivity (specificity) of each ultrasound parameter to predict postpartum hysterectomy of patients with placenta accreta was 100% (25.53%), 77.78% (54.26%), 61.11% (73.40%), 83.33% (48.94%), respectively, the positive predictive value (negative predictive value) was 20.45% (100%), 24.54% (92.73%), 30.56% (90.79%), 23.81% (93.88%). The loss of retroplacetal clear zone has high sensitivity and low specificity in predicting the postpartum hysterectomy in patients with placenata accreta, and the presence of ″moth-eaten″ lacunar spaces has high sensitivity and specificity.

Ultrasound is important for the prenatal diagnosis of accreta placentation. The loss of retroplacental clear zone in the prenatal diagnosis of placenta accreta has high sensitivity and low specificity, and the presence of ″moth-eaten″ lacunar spaces has high specificity, and has some correlation with the pregnancy outcomes of patients with palcenta previa. Performing routine detailed placenta ultrasound examination for women with prior caesarean delivery presenting with a low-lying or a placenta previa is essential in improving the detection rate of placenta accreta.