title: Measurement of elasticity of normal placenta using the Virtual Touch quantification technique.
abstract: OBJECTIVE
  The aim of this study was to measure the elasticity of normal placentas using the Virtual Touch quantification (VTQ) technique.
  
  
  METHODS
  This study was approved by the Institutional Ethics Committee. Fifty randomly selected, healthy pregnant women in their second trimester and 50 randomly selected, healthy pregnant women in their third trimester with a single fetus were included, and their placentas underwent VTQ through shear wave velocity (SWV) measurements. The measurements were performed at different locations to sample different areas of the placenta. Measurements were performed 3-4 times in each location, the mean shear wave velocities were calculated without the highest and lowest values of measurements in each region, and the results were compared.
  
  
  RESULTS
  The SWV of the placenta was 0.983±0.260 m/sec, and the minimal and maximal speed was 0.63 m/sec and 1.84 m/sec, respectively. There was no significant difference between the second and third trimester of VTQ of the placenta in terms of SWV (0.978±0.255 m/sec vs. 0.987±0.266 m/sec, P=0.711). The maternal age between second and third trimester was 27.9±4.3 years and 29.2±4.4 years, respectively; there was no significant difference between them (P=0.159).
  
  
  CONCLUSIONS
  The results of this study show that the SWV of normal placenta tissue is 0.983±0.260 m/sec, it has little variation between the second and third trimesters, and the VTQ technique may potentially play an additional role in placenta evaluation.
authors.affiliation: Department of Ultrasound, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors.forename: Size
authors.identifier: 0000-0002-1086-764X
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Ultrasound, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors.forename: Ruixia
authors.identifier: 0000-0002-9493-9638
authors.initials: R
authors.lastname: Nan
authors.affiliation: Department of Obstetrics and Gynecology, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors.forename: Yueping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Ultrasound, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors.forename: Xiaojing
authors.identifier: 0000-0003-0330-7772
authors.initials: X
authors.lastname: Cui
authors.affiliation: Department of Ultrasound, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors.forename: Xian
authors.identifier: 0000-0002-0175-3499
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Ultrasound, Affiliated Hospital of Hainan Medical College, Haikou, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhao
keywords: Acoustic radiation force impulse; Elasticity imaging techniques; Placenta; Shear wave velocity; Ultrasonography; Virtual Touch quantification