Evaluation of the stiffness of normal cervix and its change with different factors using transvaginal two-dimensional shear wave elastography under strict quality control

Relationship between endometriosis and uterine cervical elasticity assessed using ultrasound strain elastography

PURPOSE

Internal cervical os (ICO) stiffness is related to menstrual pain, a key symptom of endometriosis. The study evaluated whether women with endometriosis have a stiffer ICO than unaffected women.

METHODS

A retrospective cross-sectional analysis was conducted using prospectively collected data from women with and without endometriosis, spanning from June 2020 to September 2022. Endometriosis was diagnosed through clinical and ultrasound evaluations, with histological confirmation in a subset of participants. Strain elastography (SE) was employed to measure tissue elasticity in four cervical regions of interest: the ICO and the anterior, posterior, and middle cervical compartments (ACC, PCC, and MCC, respectively). Tissue elasticity was quantified using a color-based scoring system ranging from 0.1 (blue, indicating less elasticity) to 3.0 (red, indicating greater elasticity).

RESULTS

Overall, 287 women were included, with 157 diagnosed with endometriosis and 130 controls. On SE, women with endometriosis exhibited a lower color score (mean±standard deviation), indicating lower elasticity, for the ICO (0.56±0.28 vs. 0.70±0.26, P=0.001) and PCC (0.69±0.30 vs. 0.80±0.27, P=0.002). Additionally, they had a lower ICO/MCC ratio (0.45±0.28 vs. 0.60±0.32, P=0.001) and ICO/ACC ratio (0.68±0.42 vs. 0.85±0.39, P=0.001). Multiple logistic regression analysis revealed that endometriosis was associated with the ICO color score (odds ratio, 0.053; 95% confidence interval, 0.014 to 0.202; R2=0.358; P=0.001), even after adjusting for confounding factors like the presence of myomas (P=0.040) and the use of hormonal therapy (P=0.001). The results were corroborated in women with histologically confirmed endometriosis (n=71).

CONCLUSION

The findings suggest a potential relationship between a stiffer ICO and endometriosis.

Preliminary application of real-time shear wave elastography to evaluate endometrial receptivity and predict pregnancy outcome

BACKGROUND

Endometrial receptivity is crucial for the establishment of a healthy pregnancy outcome. Previous research on endometrial receptivity primarily examined endometrial thickness, endometrial echo types, and endometrial blood supply.

OBJECTIVE

To explore the differences in the elastic modulus of the endometrium in women with various pregnancy outcomes by real-time shear wave elastography (SWE) and to investigate its application value in evaluation of endometrial receptivity.

METHODS

A total of 205 pregnant women who were admitted at Wenzhou People's Hospital between January 2021 and December 2022 were selected. Three-dimensional transvaginal sonography and real-time shear wave elastography were performed in the proliferative phase and receptive phase of the endometrium, and the average elastic modulus of the endometrium in the two phases was obtained and compared. According to whether the pregnancy was successful or not, the participants were divided into the pregnancy group (n= 72) and non-pregnancy group (n= 133), and the differences in intimal thickness, 3D blood flow parameters, and average elastic modulus of intima were compared between the two groups.

RESULTS

The average elastic modulus of the endometrium in the proliferative phase and receptive phase was (23.92 ± 2.31) kPa and (11.82 ± 2.24) kPa, respectively, and the difference was statistically significant P< 0.05. The average elastic modulus of the endometrium in the pregnancy group and non-pregnancy group was (9.97 ± 1.08) kPa and (12.82 ± 2.06) kPa, respectively, and the difference was statistically significant P< 0.05. The area under the curve of predicting pregnancy by the average elastic modulus of the endometrium in the receptive phase was 0.888 (0.841∼0.934), with corresponding P value < 0.05. The critical value was 11.15, with a corresponding sensitivity of 81.7% and specificity of 78.2%.

CONCLUSION

Real-time shear wave elastography can quantitatively evaluate endometrial elasticity, indirectly reflect the endometrial phase, and provide a new diagnostic concept for evaluating endometrial receptivity and predicting pregnancy outcome in infertile patients.