Quantitative analysis of collagen architecture in the human uterotubal junction (UTJ) using optical coherence tomography imaging (OCT)

Abnormal uterotubal junction (UTJ) structure is implicated in the pathogenesis of endometriosis and infertility; however, this relationship remains poorly characterized. We quantitatively characterized the orientation of collagen fiber bundles in the UTJ using optical coherence tomography (OCT). UTJ tissue from nine individuals undergoing hysterosalpingectomy were collected and longitudinally opened to expose the lumen. Volumetric OCT images were acquired from proximal (uterine), middle, and distal (isthmic) UTJ segments. Images were preprocessed to enhance contrast and continuity of fiber bundles. Local fiber bundle orientation was extracted from Sobel-filtered intensity gradients. Orientation values were binned corresponding to the expected alignment of collagen fiber bundle groups in UTJ smooth muscle: longitudinal (0°–30°), oblique (30°–60°), and circumferential (60°–90°). Proportions were plotted as a function of depth, and depth-dependent trends in alignment were compared across UTJ segments using mixed-effects models. Measurements revealed a prominent inner longitudinal muscle layer which emerged proximally and thinned distally, and an outer muscle layer composed of oblique uterine fiber bundles proximally and a mixed oblique-circumferential contribution distally. These findings provide the first quantitative, depth-resolved analysis of UTJ collagen architecture and establish an analytical framework which can support future studies investigating how UTJ structure relates to function and disease. Similar content being viewed by others

We thank Meredith Hendry, Kayla Bissonette, and the Banner University Medical Center—Tucson Pathology Department for their role in providing samples. The first author of this project (D.J.L) would like to thank the Margaret “Peg” Moseley family for their support through the Phoenix Chapter of the ARCS® Foundation Inc., and the National Institutes of Health / NICHD for their training support (F30HD115314). Funding Eunice Kennedy Shriver National Institute of Child Health and Human Development, F30HD115314, 1R01HD118973, Achievement Rewards for College Scientists Foundation, Margaret “Peg” Moseley Scholarship, The Leonard Lauder Family Office, National Cancer Institute, 1R01CA260399, U.S. Department of Defense, W81XWH1810371 #OC170427. Author information Authors and Affiliations Corresponding author Ethics declarations Competing interests J.H. and J.B. are co-inventors on U.S. patents 12,144,642 and 10,939,864. J.B. serves on the Medical and Scientific Advisory Board of the National Ovarian Cancer Coalition. The other authors declare no conflicts of interest. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Rights and permissions Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. About this article Cite this article Long, D., Klein, R., Johnson, M. et al. Quantitative analysis of collagen architecture in the human uterotubal junction (UTJ) using optical coherence tomography imaging (OCT). Sci Rep (2026). https://doi.org/10.1038/s41598-026-57852-0 Received: Accepted: Published: DOI: https://doi.org/10.1038/s41598-026-57852-0