Multi-parametric acoustic imaging of cervix for more accurate detection of patients at risk of preterm birth

Abstract

Preterm delivery (PTD) can cause serious health problems and can jeopardize the life of a newborn. Diagnostic imaging of cervix is mostly limited to ultrasound (US), especially transvaginal ultrasound (TVUS) for measuring the cervical length and has shown low sensitivity and specificity for determining the risk of PTD. US viscoelasticity (VE) and photoacoustic (PA) imaging are commonly used quantitative functional imaging modalities which are used in conjunction with US imaging to provide additional information on tissue composition and functionality. Cervical ripening, or shortening and softening of the cervix, is indicative of the stage of the delivery. During the ripening process, the cervical tissue undergoes microstructural changes, such as the disorganization of the collagen network. We developed a tri-modal transvaginal US, PA, and VE imaging system and evaluated this system to monitor phantom and murine cervical changes. Specifically, in this study, we demonstrate the utility of spectroscopic PA (sPA) to monitor cervical tissue hydration and collagen disorganization. The sPA is capable of measuring tissue vascularization and oxygenation, which could serve as valuable biomarkers of cervical insufficiency and ripening. The combined probe can provide a range of clinical biomarkers characterizing the microstructural, functional and molecular changes in the cervical tissue. These biomarkers can potentially enhance the identification and prognosis of patients who are at risk of PTD.