Ultrasound elastography can detect placental tissue abnormalities
Purpose: In this observational cohort study, we examined the utility of elastography to evaluate the fetus and placenta.
Methods: Pregnant women in their third trimester of pregnancy, by which time the placenta has formed, were included in this study. A total of 111 women underwent ultrasound examinations, including elastography. Elastographic evaluation was performed using two protocols. First, the placental index (PI) was measured, which quantitatively assesses the hardness of tissue. Second, regions of interest (ROI) were categorized into 3-step scores according to the frequency of the blue area (hardness of placental tissue score [HT score]), which is a qualitative method. After delivery, 40 of the 111 placentas were pathologically examined.
Results: There was a statistically significant correlation between the PI of the placental tissue, as evaluated by ultrasound elastography and the z score of birth weight (p<0.01). Pathological abnormalities of the placenta were identified in 40.0% of the HT score 3 group, representing 6 of the 15 patients, and in 6.7% of the HT score 1 group, representing only 1 of the 15 patients.
Conclusions: Placental hardness as determined by elastography correlates with both lower estimated fetal body weight and a higher risk of pathological abnormalities in the placenta. These results suggest that ultrasound elastography may be a useful screening modality for identify high-risk pregnant women who require further evaluation and can be applied to reduce perinatal risk.