[Evaluating the pregnant cervix uteri by ultrasound with computer-assisted texture analysis]

Cervical ripening during pregnancy is associated with ultrastructural alterations, presumably correlated with structural changes of the ultrasonographic image. Analysing these changes might allow conclusions on cervical consistence without necessarily performing manual examination.

Ultrasound findings of 112 patients with normal pregnancy (14th to 41st week of pregnancy) have been compared to those of 57 patients admitted because of cervical insufficiency (20th to 35th week). A representative region of interest was analysed using a computer based texture analysing system ("Ultra" written in "Interactive Data Language"). 125 parameters derive from various texture algorithms: 1st order gray scale statistics, row, slit and area statistics, gradient statistics, cooccurrence statistics. By means of factor and multiple regression analysis those parameters could be determined, which contribute significantly to the clinical assessment of cervical consistence. Weighting these parameters a so called texture score (TS) and--implementing the other parameters of the Bishop-Score (BS)--a texture based cervical score (TBCS) could be established.

Manual assessment of cervical consistence could be reproduced excellently by noninvasive texture analysis. TBCS was highly correlated to BS, correlation to remaining duration of pregnancy (RDOP) was highly significant for TBCS but insignificant for BS.

Manual assessment of cervical consistence may be replaced by noninvasive texture analysis. Using RDOP as target parameter TS and TBCS turn out to be superior to manual assessment and BS respectively.

Computer aided texture analysis of cervical ultrasound imaging provides a useful information, which can be obtained easily and might help to reduce palpatory controls and increase the accuracy of prediction of pregnancy prolongation.