title: A novel approach to assessing fetal tissue stiffness using virtual touch tissue quantification.
abstract: OBJECTIVE
  Virtual touch tissue quantification (VTTQ) has been widely used in adults, but its application in fetuses has not been reported. The purposes of this study were to describe the normal shear wave velocity (SWV) values of fetal brain, lung, and liver by VTTQ and to examine the clinical usefulness of this procedure in THE evaluation of gestational age-related SWV changes in the fetal brain, lung and liver.
  
  
  METHODS
  One hundred fetuses were enrolled in this study and were evaluated at 18 weeks (second trimester) and 35 weeks (third trimester) during pregnancy. The SWV was measured at the cerebral parenchyma, thalamus, cerebellum, choroid plexus, left lung, right lung, right and left lobe of the liver in each participant.
  
  
  RESULTS
  The SWV at the cerebral parenchyma were all significantly greater in the third trimesters than in the second trimesters (3.29+/-1.05 vs. 2.22+/-0.97 m/s, p<0.001), while the velocities at thalamus, cerebellum, choroid plexus, left lung, right lung, right lobe of the liver and left lobe of the liver did not differ between the second and the third trimesters (p>0.05). Moreover, the SWV at the cerebral parenchyma correlated significantly with gestational age (r=0.47, p<0.001).
  
  
  CONCLUSIONS
  VTTQ can provide numerical measurements of fetal brain, lung and liver stiffness and can effectively and objectively indicate gestational age-related changes in cerebral parenchyma stiffness by measuring SWV values.
authors.affiliation: Department of Ultrasound, The First People's Hospital of Yancheng, Yancheng,P.R.China.
authors.forename: Xiao-Zhi
authors.initials: XZ
authors.lastname: Zheng
authors.affiliation: Department of Ultrasound, The First People's Hospital of Yancheng, Yancheng,P.R.China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Ultrasound, Jiangsu Province Tumor Hospital, Nanjing, Jiangsu Province, P.R. China. tanxuyanzxz@163.com.
authors.forename: Xu-Yan
authors.initials: XY
authors.lastname: Tan
mesh_terms: D000375:Aging / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014584:User-Computer Interface; D014781:Viscera / Q000000981:diagnostic imaging* / Q000196:embryology / Q000502:physiology*