Diagnosis of Prenatal MRI in Placenta Implantation Abnormality / 中国医学影像学杂志

ABSTRACT

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.