Transvaginal Real-Time Shear Wave Elastography in the Diagnosis of Endometrial Lesions

Shear wave elastography to assess stiffness of the human ovary and other reproductive tissues across the reproductive lifespan in health and disease†

The ovary is one of the first organs to show overt signs of aging in the human body, and ovarian aging is associated with a loss of gamete quality and quantity. The age-dependent decline in ovarian function contributes to infertility and an altered endocrine milieu, which has ramifications for overall health. The aging ovarian microenvironment becomes fibro-inflammatory and stiff with age, and this has implications for ovarian physiology and pathology, including follicle growth, gamete quality, ovulation dynamics, and ovarian cancer. Thus, developing a non-invasive tool to measure and monitor the stiffness of the human ovary would represent a major advance for female reproductive health and longevity. Shear wave elastography is a quantitative ultrasound imaging method for evaluation of soft tissue stiffness. Shear wave elastography has been used clinically in assessment of liver fibrosis and characterization of tendinopathies and various neoplasms in thyroid, breast, prostate, and lymph nodes as a non-invasive diagnostic and prognostic tool. In this study, we review the underlying principles of shear wave elastography and its current clinical uses outside the reproductive tract as well as its successful application of shear wave elastography to reproductive tissues, including the uterus and cervix. We also describe an emerging use of this technology in evaluation of human ovarian stiffness via transvaginal ultrasound. Establishing ovarian stiffness as a clinical biomarker of ovarian aging may have implications for predicting the ovarian reserve and outcomes of Assisted Reproductive Technologies as well as for the assessment of the efficacy of emerging therapeutics to extend reproductive longevity. This parameter may also have broad relevance in other conditions where ovarian stiffness and fibrosis may be implicated, such as polycystic ovarian syndrome, late off target effects of chemotherapy and radiation, premature ovarian insufficiency, conditions of differences of sexual development, and ovarian cancer. Summary sentence:  Shear Wave Elastography is a non-invasive technique to study human tissue stiffness, and here we review its clinical applications and implications for reproductive health and disease.

Advancements in the application of uterine ultrasound elastography

PURPOSE OF REVIEW

This article reviews recent advances in ultrasound elastography in diagnosing and evaluating the normal nongravid uterus and the infertile uterus in the gynecologic patient.

RECENT FINDINGS

Focusing on the most recent primary literature, studies have demonstrated new findings among a breadth of gynecologic clinical settings. Studies in the nongravid uterus have found that menopausal status, age, and menstrual phase have not been associated with changes in uterine tissue stiffness. Focusing on myometrial disease, there have been conflicting data regarding the ability to distinguish uterine fibroids from adenomyosis. One area of expanding research surrounding uterine elastography includes the infertile population, where ongoing studies attempt to provide a predictive model using shear wave elastography (SWE) in patients undergoing in-vitro fertilization.

SUMMARY

Ultrasound elastography has become an increasingly studied and utilized tool in assessing physiologic and pathologic processes in the field of gynecology. Evaluating tissue stiffness through strain and SWE can serve to improve diagnosis of various uterine and cervical lesions, as well as prognosticate outcomes after fertility treatments. This growing area of research will continue to establish the role and application of ultrasound elastography into clinical practice.

Evaluation of endometrial receptivity in women with unexplained infertility by shear wave elastography

OBJECTIVES

The endometrium of most unexplained infertility (UI) patients has been altered histologically. Shear wave elastography (SWE) is utilized to assess the signature of living tissue. This study aimed to explore the value of SWE in evaluating endometrial receptivity (ER) in UI patients.

METHODS

In total, 59 UI patients (UI group) and 52 normal control women (NC group) who received fertility consultation in our hospital were included between January 2022 and June 2023. We divided them into the late-proliferative phase of UI group (LPUI; n = 59), mid-secretory phase of UI group (MPUI; n = 41), late-proliferative phase of NC group (LPNC; n = 52), and mid-secretory phase of NC group (MPNC; n = 45). Transvaginal ultrasonography and SWE were performed during the LP and MP. Endometrial thickness (EMT), uterine artery pulsatility index (UA-PI), endometrial mean elasticity (E-mean), and mean shear wave velocities (SWV-mean) were measured.

RESULTS

There were significant differences in E-mean, SWV-mean, EMT, and UA-PI between the UI group and the NC group during both the LP and MP (p MPNC vs MPUI < 0.05, p LPNC vs LPUI < 0.05). E-mean and SWV-mean decreased with increasing EMT but increased with increasing UA-PI (p < 0.05). The most effective parameter for evaluating ER in UI patients is the E-mean (AUC = 0.89).

CONCLUSIONS

UI patients exhibited thinner endometrium, increased endometrial stiffness, and poor endometrial blood perfusion. E-mean was the most effective parameter to evaluate ER in UI patients. The study preliminarily proved that SWE is a promising non-invasive tool for evaluating the condition of endometrium.

CRITICAL RELEVANCE STATEMENT

This study aimed to explore the significance of endometrial elasticity measured by SWE in evaluating patients with UI. The findings revealed a correlation between EMT, UA-PI, and E-mean. Endometrial elasticity can serve as an effective indicator for predicting ER.

KEY POINTS

1. To explore the significance of endometrial elasticity in assessing patients with UI. 2. The endometrium of UI patient exhibited thinness, stiffness, and poor blood perfusion. 3. Endometrial elasticity serves as a valuable indicator for evaluating endometrial receptivity.

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.

Evaluation of endometrial thickness in breast cancer patients with tamoxifen treatment - Difference between 2-dimensional ultrasonography and elastosonography

OBJECTIVE

This study aimed to confirm the clinical significance of elastographic endometrium measurement in comparison with conventional ultrasonography for tamoxifen users with breast cancer.

MATERIALS AND METHODS

In this retrospective analysis, 98 women receiving tamoxifen as postoperative breast cancer treatment were included. Patient medical charts were reviewed, and related medical, obstetric, and gynecological information and histories relevant to breast cancer were evaluated. Patient clinical imaging data included endometrial thickness measurements using both conventional ultrasonography and elastography, and the differences between these two modalities in delta values were statistically analyzed along with possible influencing factors.

RESULTS

Endometrial thickness measured using 2-dimensional ultrasonography had a mean value of 5.81 mm (standard deviation [SD] = 3.09), and elastosonography showed a mean value of 3.07 mm (SD = 1.62). A paired t-test was conducted and a significant difference between them was confirmed (P-value <0.001). Logistic regression analysis revealed that age and duration of tamoxifen treatment significantly influenced the degree of difference between endometrial thickness measurements.

CONCLUSIONS

Elastosonography may be a more successful and useful tool for measuring actual endometrial thickness than generalized 2-dimensional ultrasonography. In clinical cases with limited use of elastosonography and consequent inability for thorough evaluation of endometrial thickness, practitioners should exercise caution in deciding whether or not to adopt invasive diagnostic procedures, such as endometrial curettage, especially for young patients of reproductive age or those with prolonged treatment of breast cancer with tamoxifen.

Quantitative Evaluation of the Normal Cervix, Cervical Cancer, and Cervical Precancerous Changes Via Real-Time Shear Wave Elastography

OBJECTIVES

The present study aims to evaluate the clinical application values of ultrasound real-time shear wave elastography (SWE) in the diagnosis and differential diagnosis of cervical cancer (CC).

METHODS

A total of 285 married female patients were screened and divided into three groups according to the results of the pathological examination and the cervical ThinPrep cytologic test: 1) the CC group (n = 94); 2) the cervical intraepithelial neoplasia (CIN) group (n = 91); and 3) the normal control group (n = 100). The maximum Young's modulus (Emax), mean Young's modulus (Emean), minimum Young's modulus (Emin), and Young's modulus stability (Esd) in each group were measured and statistically analyzed.

RESULTS

There were no statistically significant differences in Emax, Emean, Emin, and Esd values between the anterior and posterior cervical walls, premenopausal and postmenopausal women, and nonparturient and parturient women in the normal control group. The Emax, Emean, Emin, and Esd values in the CIN group showed no statistically significant differences in different periods when compared with the control group. The differences between the normal control group and the CC group were statistically significant; the CC group showed no statistically significant differences in Emax, Emean, Emin, and Esd values at different clinical stages and in different pathological types. The cutoff value of Emax for CC diagnosis, which was of the highest accuracy (89.7%), was 43.48 kpa.

CONCLUSION

Ultrasound real-time SWE can be applied to CC diagnosis.

Advances in the clinical application of ultrasound elastography in uterine imaging

Changes in tissue stiffness by physiological or pathological factors in tissue structure are identified earlier than their clinical features. Pathological processes such as uterine fibrosis, adenomyosis, endometrial lesions, infertility, and premature birth can manifest as tissue elasticity changes. In clinical settings, elastography techniques based on ultrasonography, optical coherence tomography, and magnetic resonance imaging are widely used for noninvasive measurement of mechanical properties in patients, providing valuable tool and information for diagnosis and treatment. Ultrasound elastography (USE) plays a critical role in obstetrics and gynecology clinical work because of its simplicity, non-invasiveness, and repeatability. This article reviews the recent progress of USE in uterine tumor diagnosis (especially early diagnosis and treatment effect evaluation), prediction of preterm birth, and intrauterine insemination. We believe that USE, especially shear wave elastography, may serve as a potential means to assess tissue stiffness, thereby improving the diagnosis and treatment of adenomyosis, fibroids, endometrial lesions, cervical cancer, and precise management of preterm birth and intrauterine insemination monitoring.

Value of Strain-Ratio Elastography in the Diagnosis and Differentiation of Uterine Fibroids and Adenomyosis

Benign uterine disorders, including uterine fibroids (UF) and adenomyosis (AM), can impact the life quality and fertility of women of reproductive age. Transvaginal ultrasound (TVUS) has long been used for their early identification, but its combined use with elastography seems to improve diagnostic accuracy of UF and AM. Thus, a prospective pilot study was conducted on 79 patients who underwent hysterectomy (25 microscopically diagnosed with AM and 53 with UF), with the aim of assessing the ability of TVUS combined with strain ratio elastography (SE) to accurately diagnose and distinguish UF and AM. Significantly higher mean and maximal strain ratio (SR) values were identified for patients with histologically confirmed AM as opposed to those with UF (p < 0.001). Diagnostic sensitivity and specificity, calculated in comparison with histology results, were higher for UF than AM. Receiver operating characteristic (ROC) analysis was applied between the two study groups, revealing cutoff values of 7.71 for mean SR and 8.91 for maximal SR, respectively, with good sensitivity and specificity parameters (100% and 96.23%; 96% and 96.23%). Our results support the use of TVUS in combination with SE for the positive and differential diagnosis of UF and AM, through identification of their particular tissue stiffness features.