Accuracy of Transvaginal Ultrasonographic Diagnosis of Retroflexed Uterus in Endometriosis, with Magnetic Resonance Imaging as Reference

Matsuda S, Shigeru Matsuda, Ichikawa M, Masao Ichikawa, Kaseki H, Hanako Kaseki, Watanabe K, Kenichiro Watanabe, Ono S, Shuichi Ono, Akira S, Shigeo Akira, Takeshita T, Toshiyuki Takeshita
Journal of Nippon Medical School = Nippon Ika Daigaku zasshi · 2022 · vol. 90(1) , pp. 26–32 · doi:10.1272/jnms.jnms.2023_90-106 · PMID:36273903 · W4307181071
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⚙ AI-generated summary by claude@2026-06, 2026-06-07 ⓘ

Transvaginal ultrasonography accurately measured uterine flexion angle, correlating strongly with MRI, but struggled to diagnose anteverted retroflexed uteruses, leading to false negatives.

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⚙ AI-generated deep summary by claude@2026-06, 2026-06-07 · read from full text ⓘ

This retrospective study evaluated how accurately transvaginal ultrasonography (TVUS) measures uterine flexion/retroflexion by retrospectively assessing TVUS and magnetic resonance imaging (MRI) measurements in 123 patients who underwent endometriosis surgery between 2012 and 2017. TVUS uterine flexion angles showed a strong positive correlation with MRI reference measurements (r = 0.86). TVUS had no false-positive diagnoses but produced 28 false-negative diagnoses of retroflexion, with all false negatives occurring in patients with anteverted retroflexed uteruses, which the authors identify as a key limitation. This paper is centrally about endometriosis—specifically, assessing TVUS accuracy for diagnosing retroflexed uterus in endometriosis using MRI as a reference.

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Abstract

BACKGROUND: Accurate diagnosis of retroflexed uterus in daily practice is essential because this condition is related to pelvic pain and deep endometriosis. Uterine flexion can be measured by transvaginal ultrasonography (TVUS), a cost-effective primary test, but the accuracy required for diagnosing retroflexed uterus is unclear. This study assessed the accuracy of TVUS for diagnosis of retroflexed uterus in patients with endometriosis and compared it with that of magnetic resonance imaging (MRI) -the gold standard for measuring the uterine axis. METHODS: The study included 123 patients who underwent endometriosis surgery in our department between 2012 and 2017. Uterine flexion angles were measured by retrospectively examining TVUS and MRI images, and the correlation was analyzed. Analysis of anteverted and retroverted uterine subgroups identified aspects of diagnosing uterine flexion with TVUS. RESULTS: Uterine flexion angles on TVUS were strongly positively correlated (r = 0.86) with MRI results. Additionally, TVUS yielded no false-positive diagnoses and 28 false-negative diagnoses of retroflexion. All false-negative diagnoses occurred in patients with anteverted retroflexed uteruses. CONCLUSIONS: TVUS was generally accurate for measuring uterine flexion angle, as indicated by its strong correlation with MRI. Misdiagnosis of anteverted retroflexed uterus was a limitation of using TVUS for retroflexion diagnosis.
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Keywords

transvaginal ultrasonography, magnetic resonance imaging, endometriosis, uterine retroflexion 2023 Volume 90 Issue 1 Pages 26-32 Details

Abstract

Background: Accurate diagnosis of retroflexed uterus in daily practice is essential because this condition is related to pelvic pain and deep endometriosis. Uterine flexion can be measured by transvaginal ultrasonography (TVUS), a cost-effective primary test, but the accuracy required for diagnosing retroflexed uterus is unclear. This study assessed the accuracy of TVUS for diagnosis of retroflexed uterus in patients with endometriosis and compared it with that of magnetic resonance imaging (MRI) -the gold standard for measuring the uterine axis. Methods: The study included 123 patients who underwent endometriosis surgery in our department between 2012 and 2017. Uterine flexion angles were measured by retrospectively examining TVUS and MRI images, and the correlation was analyzed. Analysis of anteverted and retroverted uterine subgroups identified aspects of diagnosing uterine flexion with TVUS. Results: Uterine flexion angles on TVUS were strongly positively correlated (r = 0.86) with MRI results. Additionally, TVUS yielded no false-positive diagnoses and 28 false-negative diagnoses of retroflexion. All false-negative diagnoses occurred in patients with anteverted retroflexed uteruses. Conclusions: TVUS was generally accurate for measuring uterine flexion angle, as indicated by its strong correlation with MRI. Misdiagnosis of anteverted retroflexed uterus was a limitation of using TVUS for retroflexion diagnosis. © 2023 by the Medical Association of Nippon Medical School Favorites & Alerts Recently viewed articles Predecessor

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Condition tags

endometriosis

MeSH descriptors

Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis

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