In vivo characterization of connective tissue remodeling using infrared photoacoustic spectra
Premature cervical remodeling is a critical precursor of spontaneous preterm birth, and the remodeling process is characterized by an increase in tissue hydration. Nevertheless, current clinical measurements of cervical remodeling are subjective and detect only late events, such as cervical effacement and dilation. Here, we present a photoacoustic endoscope that can quantify tissue hydration by measuring near-infrared cervical spectra. We quantify the water contents of tissue-mimicking hydrogel phantoms as an analog of cervical connective tissue. Applying this method to pregnant women in vivo, we observed an increase in the water content of the cervix throughout pregnancy. The application of this technique in maternal healthcare may advance our understanding of cervical remodeling and provide a sensitive method for predicting preterm birth.
Additional Information© 2018 The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. Paper 180516SSR received Aug. 26, 2018; accepted for publication Nov. 14, 2018; published online Dec. 5, 2018. We thank Professor James Ballard for closely reading the paper, Li Lin for technical support, and Alicia Brueggemann for help in the study. This project was supported in part by the March of Dimes Prematurity Research Center (3125-17303A) and the National Institutes of Health, Grant Nos. DP1 EB016986 (NIH Director's Pioneer Award) and R01 CA186567 (NIH Director's Transformative Research Award). Disclosures: K. Maslov has a financial interest in Microphotoacoustics, Inc. L. V. Wang has a financial interest in Microphotoacoustics, Inc., CalPACT, LLC, and Union Photoacoustic Technologies, Ltd., which, however, did not support this work.
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