Detection of Human Cervical Ripening with Estimates of Tissue Attenuation: A Pilot Methodology Development Study

Background: Preterm birth continues to be a leading cause of perinatal mortality and a major cause of developmental delay leading to significant economic burden to society. Cervical change has been recognized as an early indicator for an increased risk of preterm birth. Fibrillar collagen is the main structural protein contributing to tissue resistance in cervical tissue leading to preterm labor. Presently there is no method to detect collagen changes in the cervix non-invasively.  We have demonstrated in our prior work that the decreased collagen concentration associated with cervical ripening clearly affected ultrasound scattering and attenuation from cervix tissue microstructure in the animal model. Aim: To develop the methodology to estimate cervical attenuation and scattering in human pregnancy. Methods: Transvaginal ultrasound images were obtained from 53 pregnant women and compared to two tissue mimicking phantoms using the same presets and protocol. The beam formed images were saved as DICOM data and converted offline to radio frequency ultrasound data. The radiofrequency data was analyzed with a Matlab® program. Results: Using an attenuation processing method we previously developed,²⁷ there was a trend towards decreased cervical attenuation as the gestational age advanced towards term. Implications: It is possible to acquire useable human cervical raw radio frequency data with a clinical ultrasound system to detect microstructural tissue changes consistent with cervical ripening in human pregnancy.