Application of strain elastography ultrasound to the endometrium of normal women

While there is a scarcity of studies utilizing strain elastography (SE) for the endometrium, commonly used gynecologic ultrasound instruments are equipped with built-in elastography modalities, primarily SE. With the objective of facilitating comprehensive examinations for gynecologic patients on a single ultrasound instrument, we undertook this study. Therefore, our aim was to study the value of SE ultrasonography in the assessment of endometrial elasticity in normal women.

Three hundred and twenty normal women were recruited at our hospitals from November 2021 to December 2022. Each volunteer underwent a transvaginal two-dimensional (2D) and SE ultrasound during either the endometrial proliferative or secretory phase. The 2D ultrasound indices obtained included endometrial thickness, echo type (type A, B, and C), and blood flow grading (grades 0, 1, 2, and 3). SE indices obtained included endometrial strain values, myometrial strain values, and endometrial strain ratios. Differences in endometrial ultrasound indices between different menstrual cycles and different age groups were compared.

Comparison of 2D ultrasound parameters revealed that endometrial thickness in the proliferative phase endometrium group was smaller than that in the secretory phase endometrium group, with a statistically significant difference. Additionally, there was a statistically significant difference in endometrial echo types between the two groups, while the disparity in endometrial blood flow grading was not significant. Regarding SE parameters, the median and mean values of endometrial strain ratio in the proliferative phase endometrium group were smaller than those in the secretory phase endometrium group, showing a statistically significant difference. However, there were no significant differences observed between the two groups in endometrial strain and myometrial strain in the fundus. Furthermore, there were no significant differences in any of the endometrial ultrasound indices among the different age groups.

SE can reflect changes in endometrial stiffness in different menstrual cycles and is an important tool for assessing endometrial softness.