title: Estimation of shear wave speed in the human uterine cervix.
abstract: OBJECTIVE
  To explore spatial variability within the cervix and the sensitivity of shear wave speed (SWS) to assess softness/stiffness differences in ripened (softened) vs unripened tissue.
  
  
  METHODS
  We obtained SWS estimates from hysterectomy specimens (n = 22), a subset of which were ripened (n = 13). Multiple measurements were made longitudinally along the cervical canal on both the anterior and posterior sides of the cervix. Statistical tests of differences in the proximal vs distal, anterior vs posterior and ripened vs unripened cervix were performed with individual two-sample t-tests and a linear mixed model.
  
  
  RESULTS
  Estimates of SWS increase monotonically from distal to proximal longitudinally along the cervix, they vary in the anterior compared to the posterior cervix and they are significantly different in ripened vs unripened cervical tissue. Specifically, the mid position SWS estimates for the unripened group were 3.45 ± 0.95 m/s (anterior; mean ± SD) and 3.56 ± 0.92 m/s (posterior), and 2.11 ± 0.45 m/s (anterior) and 2.68 ± 0.57 m/s (posterior) for the ripened group (P < 0.001).
  
  
  CONCLUSIONS
  We propose that SWS estimation may be a valuable research and, ultimately, diagnostic tool for objective quantification of cervical stiffness/softness.
authors.affiliation: Medical Physics Department, University of Wisconsin, Madison, WI, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Carlson
authors.forename: H
authors.initials: H
authors.lastname: Feltovich
authors.forename: M L
authors.initials: ML
authors.lastname: Palmeri
authors.forename: J J
authors.initials: JJ
authors.lastname: Dahl
authors.forename: A
authors.initials: A
authors.lastname: Munoz del Rio
authors.forename: T J
authors.initials: TJ
authors.lastname: Hall
mesh_terms: D000704:Analysis of Variance; D002584:Cervix Uteri / Q000000981:diagnostic imaging / Q000473:pathology*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods; D005260:Female; D006801:Humans; D007044:Hysterectomy; D010812:Physical Stimulation / Q000379:methods*; D011247:Pregnancy; D047928:Premature Birth / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: cervix; preterm birth; shear wave speed; ultrasound