title: Quantitative cervical elastography during pregnancy: influence of setting features on strain calculation.
abstract: OBJECTIVE
  To evaluate the influence on feasibility and reliability of quantitative tissue Doppler imaging (TDI)-based cervical elastography of the cycle phase and of the derivative pitch (DP) selected during tissue strain (TS) calculation across all three trimesters of pregnancy.
  
  
  METHODS
  The pilot study included 17 patients collected between the 12th and the 42nd week of gestation. The TS was measured by a single operator by quantitative elastography. The influence of DP values (5, 10, 15, and 20 mm) and phase (compression versus relaxation) was tested after a cycle of freehand compression and relaxation of the cervix through the vaginal probe. Feasibility and intra-operator intraclass correlation coefficient (ICC) agreement for strain measurement were also evaluated for every setting used.
  
  
  RESULTS
  TS values were inversely correlated with DP and were slightly higher if measured during a compression phase. TDI-based cervical elastography was feasible in all cases. Reliability for the process of strain calculation of different raw datasets was very good (ICC agreement ranging between 0.79 and 0.87), while excellent considering the same raw dataset (ICC agreement ranging between 0.93 and 0.95).
  
  
  CONCLUSIONS
  The DP and cycle phase influenced the strain values calculated. Nonetheless, TDI-based cervical elastography was feasible and reliable for all the settings considered.
authors.affiliation: Frauenklinik, Mathias-Spital Rheine, Frankenburgstr. 31, 48431, Rheine, Germany. fruscal@libero.it.|St. Franziskus-Hospital, Hohenzollernring 72, 48145, Münster, Germany. fruscal@libero.it.
authors.forename: Arrigo
authors.initials: A
authors.lastname: Fruscalzo
authors.affiliation: Clinic of Obstetrics and Gynaecology, University Hospital of Udine, P.le S. M. Della Misericordia 1, 35100, Udine, Italy. ambrogio.londero@gmail.com.
authors.forename: Ambrogio P
authors.initials: AP
authors.lastname: Londero
authors.affiliation: Klinik für Frauenheilkunde und Geburtshilfe, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany. schmitzr@ukmuenster.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Schmitz
mesh_terms: D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D054459:Elasticity Imaging Techniques; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D010865:Pilot Projects; D011247:Pregnancy; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal
keywords: Cervical elastography; Cervix uteri; Derivative pitch; Pregnancy; Reproducibility of results; Ultrasonography