Elastography Improves the Diagnostic Accuracy of Sonography in Differentiating Endometrial Polyps and Submucosal Fibroids

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 use of real time strain endometrial elastosonography plus endometrial thickness and vascularization flow index to predict endometrial receptivity in IVF treatments: a pilot study

BACKGROUND

The usefulness of endometrium strain elastosonography (SE) for the evaluation of endometrial receptivity in women undergoing in vitro fertilization (IVF) remains controversial. The objective of this prospective, observational study was to evaluate the correlation between endometrial thickness (EMT) and its related strain (ESR) on the day of ovulation triggering (hCG-d) and in vitro fertilization outcomes. Additionally, 3D Power Doppler vascular indices (3DPDVI) were also analysed.

METHODS

We included all the patients undergoing fresh IVF-single blastocyst transfer cycle from January 2021 to August 2021 at our center. On hCG-d, after B-mode scanning was completed to measure the EMT, the mode was changed to elastosonography to evaluate the ESR (ratio between endometrial tissue and the myometrium below). At the end of examination, the Endometrial Volume (EV) and 3DPDVI (vascularization index [VI], flow index [FI] and vascularization flow index [VFI]), were assessed. Statistical analysis was completed using STATA MP16 software.

RESULTS

A total number of 57 women were included. Based on the EMT on hCG-d, women were divided into two groups, Group 1: <7 mm and Group 2 ≥ 7 mm. Women with EMT < 7 mm had a significantly higher ESR (p = 0.004) and lower pregnancy rate (p = 0.04). Additionally, low ESR values were correlated with high VFI values (rho = -0.8; 95% CI = -0.9- -0.6; p < 0.0001) and EMT ≥ 7 mm could be predicted by low ESR (OR = 0.01; 95% CI = 0.01-0.30; p = 0.008, area under the ROC curve: 0.70). After all, in multiple logistic regression analysis, low values of ESR (p = 0.050) and high values of EMT (p = 0.051) on hCG-d had borderline statistical effects on pregnancy rate.

CONCLUSIONS

The ESR may be useful to improve the ultrasound evaluation of the endometrial quality in infertile women candidates to IVF/ICS. Given the small sample size of our study, the usefulness of strain elastosonography in this patients, needs further investigation.

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.

In Search of an Imaging Classification of Adenomyosis: A Role for Elastography?

Adenomyosis is a complex and poorly understood gynecological disease. It used to be diagnosed exclusively by histology after hysterectomy; today its diagnosis is carried out increasingly by imaging techniques, including transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI). However, the lack of a consensus on a classification system hampers relating imaging findings with disease severity or with the histopathological features of the disease, making it difficult to properly inform patients and clinicians regarding prognosis and appropriate management, as well as to compare different studies. Capitalizing on our grasp of key features of lesional natural history, here we propose adding elastographic findings into a new imaging classification of adenomyosis, incorporating affected area, pattern, the stiffest value of adenomyotic lesions as well as the neighboring tissues, and other pathologies. We argue that the tissue stiffness as measured by elastography, which has a wider dynamic detection range, quantitates a fundamental biologic property that directs cell function and fate in tissues, and correlates with the extent of lesional fibrosis, a proxy for lesional "age" known to correlate with vascularity and hormonal receptor activity. With this new addition, we believe that the resulting classification system could better inform patients and clinicians regarding prognosis and the most appropriate treatment modality, thus filling a void.

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.

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).

Sonoelastography for pelvic metastatic malignant pheochromocytoma: A case report

Pheochromocytoma are tumors arising from the chromaffin tissue located in the adrenal medulla and are associated with typical symptoms and signs. Occasionally, metastasis, defined as the presence of tumor cells at sites other than the original site, secondary to pheochromocytoma have been reported. Pelvic metastatic malignant pheochromocytoma has rarely been reported in the English literature. Here, we have reported a very rare case of pelvic metastatic malignant pheochromocytoma, with particular focus on sonoelastographic features.

Elastography of Endometrium in Women Taking Tamoxifen: A New Approach to an Old Diagnostic Problem

Tamoxifen is a commonly used selective estrogen receptor modulator applied in the treatment for breast cancer. However, in the endometrium, Tamoxifen stimulates tissue growth, cellular transformation, the migration of the cells, and metastatic potential in endometrial cancer. Considering that uterine cancer is the most common neoplasm of the reproductive tract and the third most common neoplastic disease in women, the aim of this study was to investigate if applying elastography in examining the endometrium was beneficial for uterine cancer screening protocols in women on selective estrogen receptor modulator therapy. This study was based on the execution of a classic assessment of the endometrium that included the evaluation of the following: echogenicity, central endometrial stripe, presence of fluid in the uterine lumen, myometrium–endometrium interface, intensity of vascularization and vascular pattern. An ultrasound presentation was then processed and analyzed with elastography. The values of the elastography parameters demonstrated good consistency for the measurement of the softest endometrial layer thickness in elastography. A strong positive correlation (R = 0.56) was demonstrated between the endometrial thickness, as determined by ultrasound examination, and the softest endometrial layer in elastography (p < 0.001). The research showed that the elastography measurements of the width of the softest endometrium layer, based on a population of women taking Tamoxifen, appeared to be a promising option for endometrial cancer screening.

ACR Appropriateness Criteria® Abnormal Uterine Bleeding

This publication summarizes the relevant literature for the imaging of patients with symptoms of abnormal uterine bleeding, including initial imaging, follow-up imaging when the original ultrasound is inconclusive, and follow-up imaging when surveillance is appropriate. For patients with abnormal uterine bleeding, combined transabdominal and transvaginal ultrasound of the pelvis with Doppler is the most appropriate initial imaging study. If the uterus is incompletely visualized with the initial ultrasou2nd, MRI of the pelvis without and with contrast is the next appropriate imaging study, unless a polyp is suspected on the original ultrasound, then sonohysterography can be performed. If the patient continues to experience abnormal uterine bleeding, assessment with ultrasound of the pelvis, sonohysterography, and MRI of the pelvis without and with contrast would be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Ultrasound vibro-elastography for assessing mechanical properties of porcine reproductive tissues in an ex vivo model

BACKGROUND

The aim of this study was to use ultrasound vibro-elastography (UVE) for measuring surface wave speed and assessing mechanical properties of ex vivo porcine reproductive tissues, including the uterus, bladder, cornua and cervix.

METHODS

In UVE, a 0.1-s harmonic vibration at low frequency was generated on the tissue surface with a handheld shaker. A linear-array ultrasound probe was used to measure the resulting surface wave propagation. Surface wave speeds of tissues were measured in the frequency range of 100-300 Hz. Mechanical properties of the tissue were calculated based on wave speed dispersion with frequency.

FINDINGS

The obtained results showed that the surface wave speeds of porcine bladder, cervix, cornua and uterus increased with frequency. There were no statistically significant differences in the wave speeds or mechanical properties among the porcine bladder, cervix, cornua and uterus.

INTERPRETATION

Experimental data obtained in this study may be used as a reference to study in vivo surface wave speed or mechanical properties for porcine or human reproductive tissues.

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

PURPOSE

The purpose of this study was to evaluate stiffness changes occurring in the healthy uterine cervix according to age, parity, phase of the menstrual cycle and other factors by shear wave elastography (SWE).

METHODS

Evaluations of cervical speed and stiffness measurements were performed in 50 non-pregnant patients without gynaecological pathology using SWE transvaginal ultrasound. We performed the evaluation in the midsagittal plane of the uterine cervix with measurements at 0.5, 1 and 1.5 cm from external cervical os, at both anterior and posterior cervical lips.

RESULTS

We evaluated 44 patients by SWE and obtained a total average velocity of 3.48 ± 1.08 m/s and stiffness of 42.39 ± 25.33 kPa. We found differences in speed and stiffness according to the cervical lip and depth evaluated; thus, we observed a velocity of 2.70 m/s at 0.5 cm of depth in the anterior lip and 3.53 m/s at 1.5 cm of depth in the posterior lip (p < 0.05). We observed differences according to parity, obtaining a wave transmission speed of 2.67 m/s and 4.41 m/s at the cervical canal of nulliparous and multiparous patients, respectively (p < 0 0.002). We observed differences according to patient age (from a speed of 2.75 m/s at the cervical canal in the age group of 20-35 years to 5.05 m/s in the age group > 50 years) (p < 0.008). We did not observe differences in speed or stiffness according to the phase of the menstrual cycle, BMI, smoking status or the presence or absence of non-HPV infections.

CONCLUSIONS

The wave transmission speed and stiffness of the uterine cervix evaluated by SWE varies according to the cervical lip and depth of the evaluation as well as according to the parity and age of the patient.

Accuracy and Reproducibility of Sonoelastography for the Assessment of Fibroids and Adenomyosis, with Magnetic Resonance Imaging as Reference Standard

The aims of this prospective diagnostic evaluation study were (i) to estimate the inter-observer agreement and reproducibility of real-time sonoelastography and real-time gray-scale ultrasound in the measurement of uterine and fibroid volumes; (ii) to evaluate the agreement between real-time gray-scale ultrasound, sonoelastography and magnetic resonance imaging with respect to these outcomes; and (iii) to evaluate the diagnostic accuracy of sonoelastography in the diagnosis of uterine pathology on stored sonoelastography and gray-scale cine loops. Women without a history of uterine pathology and with the diagnosis intrauterine fibroids or adenomyosis were included. All participants underwent gray-scale ultrasound, sonoelastography and magnetic resonance imaging. Compression sonoelastography was found to have high inter-observer and inter-method agreement for the measurement of uterine and fibroid volumes. The addition of sonoelastography to gray-scale ultrasound seems to be useful in the differentiation between fibroids, adenomyosis and normal uteri as reflected by an increase in accuracy and diagnostic agreement.

Ultrasonography of uterine leiomyomas

Uterine leiomyomas or uterine fibroids are the most common gynaecological tumours and occur in about 20-50% of women around the world. Ultrasonography (USG) is the first-line imaging examination in suspected fibroids and shows high sensitivity and specificity in diagnosing this condition. Ultrasound scans can be performed transvaginally (transvaginal scan – TVS) or transabdominally (transabdominal scan – TAS); both scans have advantages and limitations, but, in general, transvaginal sonography is superior to transabdominal sonography in most cases of pelvic pathology. Whether a leiomyoma is symptomatic or not depends primarily on its size and location. During ultrasound examination, leiomyomas usually appear as well-defined, solid, concentric, hypoechoic masses that cause a variable amount of acoustic shadowing. During the examination of leiomyomas differential diagnosis is important. Some of the most common misdiagnosed pathologies are adenomyosis, solid tumours of adnexa, and endometrial polyps. Misdiagnosis of a leiomyosarcoma has the most negative consequences, presenting symptoms are very similar to benign leiomyoma, and there is no pelvic imaging technique that can reliably differentiate between those pathologies. Magnetic resonance and computer tomography might be helpful in the diagnostics of uterine leiomyoma; however, ultrasound examination is the basic imaging test confirming the existence of leiomyomas, allowing the differentiation of myomas with adenomyosis, endometrial polyps, ovarian tumours, and pregnant uterus.