Detecting cervical softness with shear wave speed estimation

Cervical remodeling begins early and the cervix progressively softens throughout pregnancy. Premature changes may be associated with preterm birth, but there is currently no clinical objective method for assessing the softness of the cervix. Shear wave speed estimation is a noninvasive technique to evaluate tissue mechanical properties. The goal of this study is to determine the discriminatory ability of shear wave speed estimation to detect differences between ripened/softened and unripened cervix samples. Hysterectomy samples (n = 22), a subset of which were ripened (n = 13), were collected from non-pregnant women. The samples were scanned with a 9L4 linear array transducer after excision parallel to the endocervical canal at the mid position along the length of the canal on both anterior and posterior halves. T-tests and receiver operating characteristics (ROC) were used to analyze the performance of SWS estimates. The SWS estimates for the unripened group at the mid position were 3.45±0.95 m/s (anterior) and 3.56±0.92 m/s (posterior), and 2.11±0.45 m/s (anterior) and 2.68±0.57m/s (posterior) for the ripened (p<;0.001). The corresponding area under the curve (AUC) were 0.91 for anterior and 0.84 for posterior. Our results suggest that shear wave speed estimation may be a potential research and diagnostic tool for quantification of cervical stiffness/softness.