Three Dimensional Tomographic Ultrasound and Doppler Studies in Morbidly Adherent Placenta

Background: Morbidly adherent placenta (MAP) describes a spectrum of disorders including adherence of all or part of placenta to uterine wall. The aim of this study was to evaluate the potential role of the 3D Tomographic Ultrasound Imaging (TUI) and Doppler studies in diagnosis of morbidly adherent placenta.

Methods: This prospective study was conducted on 50 female patients, aged from 20 to 40, who were pregnant with history of one or more caesarean section deliveries or hysterotomies, diagnosed by 2D ultrasound as placenta previa with its lower edge covering the scar of previous caesarean section (major and minor anterior), with antepartum haemorrhage, and gestational age form 28 weeks to full term. The whole placenta was scanned in a systematic fashion using both 2D grayscale and 3D power Doppler ultrasound then displayed by 3D TUI.

Results: By 2D grayscale ultrasound, the obliteration of retroplacental hypoechoic area was found in 48% of patients with sensitivity 88.89% and accuracy 94%. Placental lacunae were found in 54% of patients with sensitivity 100% and accuracy 100%. Myometrial thinning was found in 40% of patients with sensitivity 74.07% and accuracy 86% and interruption of bladder uterine interface was found in 28% of patients with sensitivity 51.85% and accuracy 74%. By 2D colour Doppler study, the vascular gab was found in 40% of patients with sensitivity 74.07% and accuracy 86%. By 3D power Doppler study, vascularity was found in 26% of patients with sensitivity 96.3% and accuracy 96% and bridging vessel was found in 26% of patients with sensitivity 48.15% and accuracy 72%. Tomographic ultrasound image could predict MAP presence with 96.3% sensitivity and accuracy reach 98%.

Conclusion: The 3D TUI technique facilitates the evaluation of the myometrial thickness and the depth of placental invasion due to much better differentiation between various tissues compared to the conventional 2D. The 3D TUI is a useful adjunctive tool to the 3D power Doppler or color Doppler to refine the diagnosis of MAP.