Influence of epidemiological characteristics (age, parity and other factors) in the assessment of healthy uterine cervical stiffness evaluated through shear wave elastography as a prior step to its use in uterine cervical pathology

SonoElastoColposcopy: A New Tool for Cervical Dysplasia Assessment

Background/Objectives: Up to 30% of cervical dysplastic lesions are missed by colposcopy alone. We performed a comparative evaluation of the diagnostic capacity for identifying cervical dysplastic lesions between shear wave elastography (SWE) of the endocervix and exocervix, defined as SonoElastoColposcopy (SEC), and colposcopy. Methods: A prospective observational study was conducted in 84 patients indicated for cervical conization surgery (presence of cervical intraepithelial neoplasia 2 or 3 (CIN-2 or 3), adenocarcinoma in situ (AIS), or high-grade suspicious lesions). All patients underwent colposcopy with lesion identification and biopsy, and SEC and SWE evaluation of the endocervix and exocervix with measurement of lesion stiffness (KPa). Cervical lesions identified by colposcopy or SEC were localized in quadrants, and a comparative evaluation of the diagnostic capacity of both techniques was performed in relation to the anatomical pathology of the cone biopsy. Results: A total of 82 women were evaluated (two cases were lost). The mean age was 38.84 ± 8.44 years. Colposcopy was adequate in 95.12% of cases. In SEC, we observed an elasticity in the lesion area of 105.42 ± 36.32 KPa compared to 19.98 ± 9.29 KPa (p < 0.0001) in the healthy area of the exocervix. In the endocervix, the results were 109.8 ± 40.86 KPa versus 18.5 ± 9.07 KPa (p < 0.0001), respectively. The concordance for colposcopy was 0.456 compared to 0.815 (p < 0.05) for SEC. Conclusions: SEC demonstrates a better ability to identify the area of cervical dysplastic lesions than colposcopy.

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.

Comparing the effect of FUAS and myomectomy on the elasticity of myometrium around targeted uterine fibroid

BACKGROUND

Focused ultrasound ablation surgery (FUAS) has been widely employed to treat patients with uterine fibroid (UF). This study aimed to estimate myometrial stiffness changes in patients who received FUAS for UFs or myomectomy (ME) and compare the recovery of surrounding myometrium between FUAS and ME groups. Our results may provide more evidence for guiding the proper conception timing in patients with UF.

METHODS

This study enrolled 173 patients from May 2022 to August 2023. Shear wave elastography (SWE) was used to dynamically monitor myometrial elasticity changes in patients before and after surgery. Moreover, our study monitored and analyzed the stiffness changes in the targeted fibroid after FUAS, as well as in the myometrium around after FUAS or ME.

RESULTS

The stiffness of the myometrium around the resected fibroid was significantly higher than at the preoperative level until 6 months. Conversely, the stiffness of the surrounding myometrium was only temporarily increased 1 day after FUAS. The comparison between FUAS and ME groups regarding the stiffness of the surrounding myometrium showed that nonsignificant differences were detected between the two groups before the treatment. The stiffness of the surrounding myometrium in the ME group was statistically significantly higher than that of the FUAS group 1 day as well as 1, 3, and 6 months after the treatment, respectively.

CONCLUSION

The FUAS had less impact on the surrounding myometrium than the ME, which may be more conducive to the recovery of myometrial elasticity in patients with UF.

Ultrasound Elastography in Benign Gynecology: A Scoping Review

OBJECTIVE

To perform a scoping review of the literature in which ultrasound elastography (UE) has been used in benign gynecology and identify avenues for its use in future research and clinical implementations.

METHODS

A structured search of EMBASE, Medline and Cochrane databases was conducted (last search date April 15th, 2022). Eligible studies included adult participants with female pelvic anatomy. English language papers focusing on the utility of ultrasound elastography applied to benign gynecology were included. Narrative reviews, conference abstracts, and letters to the editor were excluded. Two independent reviewers screened titles and abstracts for inclusion, a third reviewer was consulted in cases of disagreement. Study quality was assessed by a checklist for study implementation and elastography technique. Extracted data included elastography technology, gynecologic application, opportunities for clinical implementation, and strengths and limitations.

RESULTS

The search returned 2026 studies. A total of 40 studies, published between 2013 and 2022, were retained for data extraction. Studies most frequently used shear wave elastography as the method of UE (n = 23), followed by strain elastography (n = 13) and acoustic radiation force impulse (n = 4). Most common clinical applications for UE were the diagnosis of adenomyosis and uterine fibroids (27.5%), assessment of pelvic floor muscle function (22.5%), and describing the elastic properties of polycystic ovaries (17.5%) and the uterine cervix (15.0%). Limitations of the technology were identified as the lack of published reference values for gynecologic organs and difficulties in assessing tissues deep to the transducer.

CONCLUSION

Future research is needed to validate the use of ultrasound elastography in gynecology under both normal and pathologic conditions.

Clinical experience with shear wave elastography (SWE) for assessing healthy uterus in a transabdominal approach

Aim of the study was to evaluate the diagnostic performance and feasibility of transabdominal ultrasound shear wave elastography (SWE) in assessing sonoelastographic features of the uterus. Twenty-seven premenopausal women were enrolled between 2021 and 2022. Transabdominal SWE measured myometrial stiffness in various uterine segments. Additionally, tissue stiffness of the quadriceps femoris muscle and autochthonous back muscle was measured. Statistical analysis employed non-parametric tests, t test, and a robust mixed linear model. Stiffness values of the uterus and the two investigated muscle types exhibited a similar spectrum: 6.38 ± 2.59 kPa (median 5.61 kPa; range 2.76-11.31 kPa) for the uterine myometrium, 7.22 ± 1.24 kPa (6.82 kPa; 5.11-9.39 kPa) for the quadriceps femoris musle, and 7.43 ± 2.73 kPa (7.41 kPa; 3.10-13.73 kPa) for the autochthonous back muscle. A tendency for significant differences in myometrial stiffness was observed concerning the type of labor mode (mean stiffness of 9.17 ± 1.35 kPa after vaginal birth vs. 3.83 ± 1.35 kPa after Caesarian section, p = 0.01). No significant differences in myometrial stiffness were observed concerning age, BMI, previous pregnancies, uterine flexion and menstrual cycle phase. Transabdominal SWE of uterine stiffness seems to be a fast and practicable method in a clinical setting. Uterine stiffness appears to be largely independent of various factors, except for the mode of delivery. However, further studies are needed to validate these results.

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.

The Application of Shear Wave Elastography to Determine the Elasticity of the Levator Ani Muscle and Vaginal Tissue in Patients With Pelvic Organ Prolapse

OBJECTIVES

The changes of the extracellular matrix of the connective tissue have significantly contributed to the incidence of pelvic organ prolapse (POP). It seems reasonable that sonoelastography could be a useful tool to evaluate the elasticity of pelvic floor tissue in patients with POP and compare it to those without POP. The main aim of this pilot study was to determine if there are differences in the elasticity of the levator ani muscle (LAM) and vaginal tissue between patients with and without POP.

METHODS

Prospective observation study, including 60 patients (30 with POP and 30 without POP). Sonoelastography was performed to evaluate the elasticity (in kilopascals, kPa) of the following regions of interest: vagina at the level of middle third of the urethra; vagina at the level of the bladder trigone; vagina in the anterior and posterior fornix; vagina at the level of middle third of the anorectal canal; posterior third of the LAM.

RESULTS

A total of 60 patients completed the study (30 with POP, 30 without POP). In the POP group, 18/30 (60%) had an anterior vaginal wall prolapse, 3/30 (10%) a uterine prolapse, 15/30 (50%) a rectocele, and 6/30 (20%) a enterocele. Patients with POP had higher elasticity in all anatomical study areas, with statistically significant differences in the anterior fornix (13.6 vs 11.2 kPa; P: .012). A multiple regression (controlling age, menopausal stage, and parity) allowed to detect statistically significant differences in the elasticity of the middle third of the urethra (P: .03) and the middle third of the anorectal canal (P: .019).

CONCLUSION

It is possible to evaluate the elasticity of the LAM and vaginal tissue using sonoelastography, detecting a higher elasticity in patients with POP than in those without POP.

The role of cervical elastography in the differential diagnosis of preinvasive and invasive lesions of the cervix

STUDY OBJECTIVE

This study aims to evaluate the role of cervical elastography in the differential diagnosis of preinvasive and invasive lesions of the cervix.

MATERIALS AND METHODS

A total of 95 women participated in this prospective study and were divided into the following groups: 19 healthy subjects (group 1) with normal cervicovaginal smear (CVS) and negative human papillomavirus test (HPV DNA), 19 women with normal cervical biopsy and normal final pathological result of cervical biopsy (group 2), 19 women with low-grade squamous intraepithelial lesion (LSIL) (group 3), 19 women with high-grade squamous intraepithelial lesion (HSIL) (group 4), and 19 women with cervical cancer (group 5). Clinical, demographic, histopathological, and elastographic results were compared between these groups.

RESULTS

Comparing groups, age (40.42 ± 8.31 vs. 39.53 ± 8.96 vs. 38.79 ± 9.53 vs. 40.74 ± 7.42 vs. 54.63 ± 12.93, p < 0.001 respectively), gravida (1.74 ± 1.33 vs. 2.16 ± 1.68 vs. 2.21 ± 1.96 vs. 2.53 ± 1.93 vs. 4.63 ± 2.17 p < 0.001 respectively), parity (1.37 ± 0.68 vs. 1.68 ± 1.20 vs. 1.58 ± 1.30 vs. 2.00 ± 1.67 vs. 3.37 ± 1.61, p < 0.001 respectively), and the proportion of patients at menopause (10.5% vs., 15.8% vs. 10.5% vs. 5.3% vs. 57.9%, p < 0.01 respectively), a statistically significant difference was found (Table 1). However, no statistically significant difference was found in the number of abortions, BMI, mode of delivery, smoking, additional disease status, history of surgery, and family history (p > 0.05) (Table  2. As a result of the applied roc analysis, mean cervical elastographic stiffness degree (ESD) was found to be an influential factor in predicting cervical cancer (p < 0.05). The mean cut-off value was 44.65%, with a sensitivity of 94.7% and a specificity of 96.1% (Table 7).

CONCLUSION

Measurement of ESD by elastography is a low-cost, easily applicable, and non-invasive indicator that can distinguish cervical cancer from normal cervical and preinvasive lesions. However, it is unsuitable for determining preinvasive cervical lesions from normal cervix.

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

BACKGROUND

The usefulness of transvaginal two-dimensional shear wave elastography (2D SWE) for cervical lesions is still uncertain. This study was to explore the value of transvaginal 2D SWE in the evaluation of the stiffness of normal cervix and its change with different factors under strict quality control (QC).

METHODS

Two hundred patients with normal cervix were included in this study and were examined using quantitative 2D SWE to evaluate cervical stiffness and its change with different factors under strict QC.

RESULTS

Intra-observer concordance of transvaginal 2D SWE parameters in midsagittal planes were acceptable with intraclass correlation coefficients higher than 0.5. Transvaginal 2D SWE parameters were significantly higher than the corresponding transabdominal parameters. 2D SWE parameters of internal cervical os were significantly higher than the corresponding parameters of external cervical os in a transvaginal midsagittal plane. 2D SWE parameters of external cervical os increased significantly over 50 years old, while these parameters of internal cervical os didn't change significantly with increasing age. 2D SWE parameters of internal cervical os of horizontal position cervix were significantly higher than those of vertical position cervix. SWE parameters of normal cervix did not change according to different menstrual cycles, parities and human papilloma virus test results.

CONCLUSIONS

Transvaginal 2D SWE under strict QC could provide quantitative, repeatable and reliable cervical stiffness information. Internal cervical os was stiffer than external cervical os. Menstrual cycles, parities and human papilloma virus test results wouldn't affect cervical stiffness. However, age and cervical positions should be taken into condition while interpreting 2D SWE results of cervical stiffness.

Prediction model for successful induction of labor by cervical strain elastography diagnosed at late-term pregnancy in nulliparous women: a prospective cohort study

BACKGROUND

The use of cervical strain elastography for nulliparous women during late-term pregnancy remains unclear. This study assesses the predictive value of late-term cervical strain elastography for successful induction of labor (IOL) in nulliparous women.

METHODS

This single-centered, prospective study included 86 patients undergoing IOL between January 2020 and March 2022. Univariate and multivariate analyses were conducted to identify predictive factors for successful IOL. The predictive values were assessed using the area under receiver operating characteristic (ROC) curves.

RESULTS

IOL was successful in 58 patients. The hardness ratio and cervical length were significantly associated with successful late-term IOL in nulliparous women. The predictive value of the combination of hardness ratio and cervical length was higher than that of cervical length alone.

CONCLUSIONS

The hardness ratio and cervical length assessed by cervical strain elastography during late-term pregnancy are predictors of the success of IOL in nulliparous women. The predictive value of the combination of hardness ratio and cervical length was higher than that of cervical length alone.

Biological role of matrix stiffness in tumor growth and treatment

In recent years, the biological role of changes in physical factors in carcinogenesis and progression has attracted increasing attention. Matrix stiffness, also known as ECM stress, is a critical physical factor of tumor microenvironment and remains alternating during carcinogenesis as a result of ECM remodeling through activation of cancer-associated fibroblasts and extracellular collagen accumulation, crosslinking and fibrosis. Different content and density of extracellular collagen in ECM endows matrix with varying stiffness. Physical signals induced by matrix stiffness are transmitted to tumor cells primarily by the integrins receptor family and trigger a series of mechanotransduction that result in changes in tumor cell morphology, proliferative capacity, and invasive ability. Importantly, accumulating evidence revealed that changes in matrix stiffness in tumor tissues greatly control the sensitivity of tumor cells in response to chemotherapy, radiotherapy, and immunotherapy through integrin signaling, YAP signaling, and related signaling pathways. Here, the present review analyzes the current research advances on matrix stiffness and tumor cell behavior with a view to contributing to tumor cell growth and treatment, with the hope of improving the understanding of the biological role of matrix stiffness in tumors.

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.

Repeatability and reproducibility of quantitative cervical strain elastography (E-Cervix) in pregnancy

Strain elastography of the uterine cervix may be useful in the diagnosis and prediction of obstetric complications. The inability to obtain quantitative results, with only the possibility of visual semiquantitative evaluation of the obtained elastograms, has been the limitation of the method thus far. E-Cervix is a software program that uses intrinsic compression to excite tissue and allows the evaluation of quantitative parameters on the basis of pixel distribution in an elastogram. The aim of this study was to assess the repeatability and reproducibility of quantitative cervical strain elastography (E-Cervix) of the uterine cervix and to assess the correlation of the obtained parameters with selected clinical features of patients in the third trimester of pregnancy. In total, 222 patients participated in the study. We assessed 5 ultrasound parameters: elasticity index (ECI), hardness ratio (HR), internal os strain (IOS), external os strain (EOS) and IOS/EOS ratio. Each study was performed according to a predetermined standardized protocol. For all assessed elastographic parameters, we obtained good intra- and interobserver reproducibility. The interclass correlation coefficient (ICC) ranged from 0.77 to 0.838 for intraobserver variability and from 0.771 to 0.826 for interobserver variability. We demonstrated a significant correlation of some obtained elastographic parameters with the basic clinical features of patients, such as age, the number of previous caesarean sections, pregnancy weight and BMI. In each case, the correlation was very low. Quantitative elastographic assessment with the use of E-Cervix is characterized by good repeatability. Some clinical features may affect the value of the parameters obtained. The clinical relevance of this interference requires further investigation.

Evaluation of Pre-malignant Lesions of the Uterine Cervix by Shear Wave Elastography: A New Diagnostic Tool

The objective of the study was to evaluate the difference in the stiffness between a healthy cervix (no pre-invasive lesions [NPILs]) and a cervix with a pre-invasive lesion (PIL). In the PIL group, we determined whether there was a difference in stiffness between the cervix with persistent low-grade lesions (>2 y, LSIL-persistent) and that with high-grade lesions (HSILs). Evaluation was performed using 2-D shear-wave elastography (SWE) in the midsagittal-plane of the uterine cervix (UC) at 0.5 cm (cervical canal, anterior and posterior cervical lips). In this prospective observational study (consecutive series), we evaluated 96 non-pregnant women: a group with PIL (LSIL-persistent, 22 cases; HSIL, 26 cases) with indications for cervical conization (48 cases) and a group without UC pathology (NPIL, 48 cases). Although we did not observe statistically significant differences (SSDs) in epidemiological characteristics, we did find an SSD in the speed and stiffness between the PIL versus NPIL groups at all evaluated depths (speed: 4.1 m/s vs 3.0 m/s, stiffness: 58.6 and 34.5kPa in the PIL and NPIL groups, respectively, p < 0.001). An SSD in speed and stiffness (speed: 4.9 m/s vs. 3.2 m/s, and stiffness: 76.1 and 38.0 kPa) between the HSIL (26 cases) and LSIL-persistent (22 cases) groups, respectively, was also detected (p < 0.001). The area under the curve of speed differentiation between a cervix with HSILs and without lesions was 73.4% (95% confidence interval [CI]: 63.1-83.7), and the best cutoff of speed was 3.25 m/s (sensitivity = 62.5%, 95% CI: 47.3-76.0), with a specificity of 75.5% (95% CI: 60.4-87.1).