[Convention Ultrasound and Contrast-enhanced Ultrasound Imaging in the Diagnosis of Placenta Implantation].

OBJECTIVES: To determine the value of conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the diagnosis of placenta residue with implantation.

METHODS: We retrospectively analyzed 112 cases of placenta remnants from Apr. 2013 to Mar. 2016, all of which were confirmed by pathological results. The cases were divided into implanted (n =74) and non-implanted (n =38) groups. We compared the characteristics of US and CEUS imaging between the two groups. Multi-variate logistic regression models were established to assess the accuracy of ultrasound imaging in predicting implantation, including the area under the curve (AUC ) of receiver operating characteristic (ROC) curves.

RESULTS: US detected intrauterine lesions, with significant differences between the two groups in the clearness of boundaries of lesions (P <0.05) . Differences between the two groups were also found in CEUS in enhanced phase, enhanced intensity, existence of clear and regular boundaries, and reduced muscle thickness in the lesion area (P <0.05). CEUS (91.1%) and US+CEUS (92.0%) had a higher prediction accuracy for placenta implantation compared with US (87.5%) (P <0.05). The AUC of CEUS (0.922) and US+CEUS (0.952) were also significantly higher than that of US (0.887) (P <0.05). No significant differences were observed between CEUS and US+CEUS.

CONCLUSION: The value of CEUS for predicting placenta implantation is higher than US.