MRI指导下对妊娠期胎盘植入不同分级的治疗作用研究

目的 探讨核磁共振成像(MRI)指导下对妊娠期胎盘植入不同分级的治疗作用.方法 选取杭州市肿瘤医院和慈溪市明峰医院2014年3月至2016年3月收治的80例超声检查发现前置胎盘并怀疑胎盘植入患者,进行MRI检查、手术和病理诊断,观察胎盘与肌层界面消失,子宫内膜变薄、T2WI胎盘内信号影及子宫轮廓外突等胎盘植入MRI征象,并统计灵敏度、特异性、阳性预测率、阴性预测率,根据MRI植入范围进行分级,判断MRI下胎盘植入不同分级对临床治疗的指导意义.结果 本实验80例超声检查发现前置胎盘并怀疑胎盘植入患者中50例被手术和病理确诊为胎盘植入.50例胎盘植入患者有46例最终被MRI正确诊断,灵敏度为92.00％,特异性90.00％,阳性预测率为93.88％,阴性预测率为87.10％.MRI特征中,胎盘与肌层交界面消失灵敏度及阴性预测率最高,分别为93.48％和86.00％,子宫肌层变薄次之,分别为89.36％及81.48％.子宫轮廓外突的特异度及阳性预测率最高均为100.00％,T2WI胎盘内信号影阳性预测率较高为88.57％.根据MRI横断图上病变最大植入面的比例进行分级,与A级成功率为100.00％相比,B级成功率为26.57％较低,(x2=17.14,P＜0.05);C级成功率为11.11％,较A级成功率低,统计学分析有显著差异(x2=18.28,P＜0.05),较B级成功率低,统计学分析无显著差异(x2=1.13,P＞0.05).结论 MRI指导下诊断方面具有显著优势,胎盘与肌层交界面消失为最佳诊断依据,胎盘植入不同分级对治疗手段选择具有指导意义,适宜临床应用推广.

Study on the treatment effect on placenta accreta grading guided by MRI in pregnancy

Objective To investigate the treatment effect on placenta accreta grading guided by magnetic resonance imaging (MRI) in pregnancy.Methods Eighty patients admitted in Hangzhou Cancer Hospital and Cixi Mingfeng Hospital and diagnosed as placenta previa by ultrasonography and suspected with placenta accreta were selected and treated with MRI examination,surgery and pathological diagnosis.MRI features of placenta previa such as disappearance of placenta and musclar layer interface,endometrial thinning,T2WI in placenta and uterine contour protrusion were observed and sensitivity,specificity,positive predictive treatment effect and negative predictive treatment effect were calculated.Grading was done according to MRI implantation range.Significance of placenta accreta grading under MRI to clinical treatment was studied.Results In 80 cases diagnosed as placenta previa by ultrasonography and suspected with placenta implantation,50 cases were surgically and pathologically diagnosed as placenta accreta.Forty-six from 50 cases of placenta accreta were eventually diagnosed by MRI correctly,with sensitivity of 92.00％,specificity 90.00％,positive predictive treatment effect 93.88％ and negative predictive treatment effect 87.10％.In MRI features,placenta and musclar layer interface disappearance had highest sensitivity and negative predictive treatment effect,which were 93.48％ and 86.00％ respectively,followed by endometrial thinning,with sensitivity of 89.36％ and negative predictive treatment effect of 81.48％.Specificity and positive predictive rate of uterine contour protrusion were highest with both of 100％.T2WI signal shadow in placenta had high positive predictive rate of 88.57％.Grading was based on maximum implantation proportion on MRI cross-sectional map.Compared with a success rate of 100.00％ for grade A,success rate of grade B was lower,which was 26.57％ (x2 =17.14,P ＜0.05).Success rate of grade C was 11.11％,which was lower than that of grade A,and difference had statistical significance (x2 =18.28,P ＜ 0.05).It was also lower than that of grade B but with no statistical significant difference (x2 =1.13,P ＞ 0.05).Conclusion Diagnosis under guidance of MRI has significant advantages,and disappearance of placenta and musclar layer interface is best diagnostic basis.Grading of placenta accreta has a guiding significance for chosing treatment methods,and is suitable for clinical application.