磁共振扩散加权成像在植入性胎盘中的诊断价值

The diagnostic value of magnetic resonance diffusion weighted imaging for implanted placenta

目的 探讨磁共振扩散加权成像(DWI)及表观弥散系数(ADC)值在各型植入性胎盘中的诊断价值。方法 收集54例植入性胎盘孕产妇,均进行常规T2WI和DWI扫描,其中DWI分别使用b值为0s/mm^2、400s/mm^2、600s/mm^2、800s/mm^2、1000s/mm^2。以手术或病理结果为标准,将植入性胎盘病例分为粘连型、植入型、穿透型三组,结合常规T2WI图像,在DWI图像中分别测量植入处组织、邻近胎盘组织和邻近子宫肌层组织的ADC值,比较这三种组织ADC值在组间及组内是否有差别。结果 54例孕产妇中32例为粘连性胎盘(59.26%),19例为植入性胎盘(35.19%),3例为穿透性胎盘(5.56%)。粘连组中植入处组织、邻近胎盘组织和邻近子宫肌层组织这三种组织平均ADC值分别为(1.8576±0.4203)×10^-3mm^2/s、(1.7876±0.2652)×10^-3mm^2/s、(1.7623±0.4699)×10^-3mm^2/s;植入组中这三种组织平均ADC值分别为(1.6607±0.2128)×10^-3mm^2/s、(1.6782±0.1799)×10^-3mm^2/s、(1.8015±0.5439)×10^-3mm^2/s;穿透组中这三种组织平均ADC值分别为(1.7703±0.1962)×10^-3mm^2/s、(1.7860±0.3272)×10^-3mm^2/s、(1.8587±0.2655)×10^-3mm^2/s。粘连组、植入组、穿透组中这三种组织的组内ADC值均无统计学差异(P>0.05),植入处组织、邻近胎盘组织和邻近子宫肌层这三种组织的ADC值在组间亦无统计学差异(P>0.05)。结论 磁共振扩散加权成像有助于植入性胎盘诊断,但植入性胎盘中不同组织的ADC值对于植入性胎盘诊断及分型无诊断价值。

Objective To investigate the diagnostic value of magnetic resonance diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)for various types of implanted placenta.Methods A total of 54 pregnant and postpartum women with placenta implantation were collected in this study.Conventional T 2WI and DWI scans were performed for all 54 cases,and the b values of DWI were 0 s/mm^2,400 s/mm^2,600 s/mm^2,800 s/mm^2 and 1000 s/mm^2,respectively.Based on the surgical or pathological results,the implanted placenta cases were divided into three groups:adhesion group,implantation group and penetration group.Combined with the conventional T 2WI images,ADC values of the implanted tissue,adjacent placental tissue and adjacent myometrium tissue were measured on the DWI images,and the differences of ADC values of the three tissues between and within the groups were compared.Results Of the 54 pregnant women,32 were adhesive placenta(59.26%),19 were implanted placenta(35.19%),and 3 were penetrating placenta(5.56%).The average ADC values of the implanted tissue,adjacent placental tissue and adjacent myometrium tissue in the adhesion group were(1.8576±0.4203)×10^-3 mm^2/s、(1.7876±0.2652)×10^-3 mm^2/s、(1.7623±0.4699)×10^-3 mm^2/s respectively.In the implantation group,the average ADC values of the three tissues were(1.6607±0.2128)×10^-3 mm^2/s、(1.6782±0.1799)×10^-3 mm^2/s、(1.8015±0.5439)×10^-3 mm^2/s.The average ADC values of the three tissues in the penetrating group were(1.7703±0.1962)×10^-3 mm^2/s、(1.7860±0.3272)×10^-3 mm^2/s、(1.8587±0.2655)×10^-3 mm^2/s.There was no significant difference in the ADC values of the implanted placenta tissue,adjacent tissue and adjacent myometrium within the adhesion group,the implantation group and the penetration group(P>0.05).There was no significant difference in the ADC values of the three tissues among the three groups(P>0.05).Conclusion DWI imaging is helpful for the diagnosis of placenta implantation,but the ADC values of different tissues in placenta implantation have no diagnostic value for the diagnosis and typing of placenta implantation.