Shear wave velocity measurement of the placenta is not limited by placental location

Introduction: Ultrasound elastography shows diagnostic promise via the non-invasive determination of placental elastic properties. A limitation is a potential for inadequate measurements from posterior placentae. This study aimed to analyse placental position's influence on measures of shear wave elastography (SWV). Methods: SWV elastography measurements were obtained via ultrasound at 24, 28 and 36 weeks gestation from 238 pregnancies. . The placental position was labelled as either anterior, posterior or fundal/lateral. Average SWV measurements (m/s) and the corresponding standard deviations (SD) were used for data analysis. Results: There was a statistically significant difference between SWV recorded from anterior (1.33 +/- 0.19)m/s and posterior (1.39 +/- 0.18)m/s placentae (p < 0.001). However, the average sampling depth between these groups was significantly different (3.98 cm vs. 5.38 cm, p < 0.001). There was no statistically significant difference between SWV when measurements were compared at similar depths, regardless of placental location. The addition of placental position to a previously developed mixed-effects model confirmed placental position did not result in improved SWV measurements. In this model, sampling depth remained the best predictor for SWV. Conclusions: This study showed that placental position does not influence the accuracy or reliability of SWV.

Automated summary

This study aimed to analyze the influence of placental position on shear wave elastography (SWV) measures. The results showed that placental position does not affect the accuracy or reliability of SWV measurements.