Ultraschall Med 2012; 33 - A729
DOI: 10.1055/s-0032-1322722

Influence of derivative pitch and cycle phase selected on quantitative cervical elastography: a pilot study

A Fruscalzo 1, AP Londero 2, R Schmitz 3
  • 1Frauenklinik, Mathias-SpitalRheine, Germany (Current adress: St. Franziskus Hospital, DE Münster)
  • 2Clinic of Obstetrics and Gynecology, University Hospital of Udine, Italy
  • 3Klinik und Poliklinik für Frauenheilkunde und Geburtshilfe, University of Münster, Germany

fruscal@libero.it

Objective:

To evaluate the influence of derivative pitch (DP) and the cycle phase selected in strain calculation on the feasibility and reliability of cervical elastography for quantitative stiffness assessment during pregnancy.

Patients and Methods:

This prospective study included a random group of 17 patients between the 12th and 42th weeks of gestation. Three raw datasets pro patients were acquired and the cervical tissue strain (TS) was twice measured as naturalstrain by a single operator using the TDI-Q (tissue Doppler imaging – Quantification) software. The influence of DP values (5, 10, 15 and 20mm) and phase (including compression versus relaxation) on the feasibility and reliability were tested.

Results:

The mean±SD gestational age, parity and cervical length were respectively 28,7±8,7 weeks, 1.5±1.4 and 41.5±9.4mm. TS values were inversely correlated with DP value, whereas the TS values were slightly higher if measured during a compression phase. The TS ranged between 0.2 and 1.1 in the compression phase and between 0.2 and 0.9 in the relaxation phase (mean value of the three raw datasets). The intra-operator variability for the same raw data twice measured resulted very high for allsubset considered (between 0.93 and 0.95). The intra-operator ICC agreement for TS measurement among three raw datasets resulted moderate to high among allsubset (ranging between 0.79 and 0.87 in the compression and between 0.79 and 0.84 in the relaxation phase). The TS measurement during the relaxation phase resulted more feasible to be performed. Overall, the TS measured in the relaxation phase with 5mm DP exhibited the best performance in terms of feasibility and reliability (intra-operator ICC agreement of 0.84).

Conclusions:

The DP and cycle phase influenced the naturalstrain values measured. The strain measurements obtained during relaxation with 5mm DP demonstrated superior feasibility and reliability.

Ultrasonography - elasticity imaging techniques - tissue elastography - tissue Doppler imaging - cervix - pregnancy - reproducibility of results