Through thick and thin: a pictorial review of the endometrium

Intrauterine injection of bioengineered hydrogel loaded exosomes derived from HUCM stem cells and spermidine prominently augments the pregnancy rate in thin endometrium rats

The endometrium is essential to the development of embryos and pregnancy. Human umbilical cord mesenchymal stem cells (HUCMSCs) are promising stem cell sources. HUCMSCs self-renew quickly and are painless to collect. Spermidine is an inherent polyamine needed for cellular and molecular processes that regulate physiology and function. HUCMSCs and spermidine (SN) may heal intrauterine adhesions. HUCMSCs were investigated for endometrial repair in rats. Composite hydrogels are used for medical exosome implantation, including their materials, properties, and embedding procedures. This study examined whether bioengineered hydrogel-loaded exosomes from HUCMSCs and spermidine prenatally improved conception rates in mice with poor endometrial lining. The data show that HUCMSC and SN provide a good experimental base for HUCMSC safety and intrauterine treatment in rats. Western blots, exosome structural analysis, pregnancy outcomes, flow cytometry, H&E staining, immunohistochemistry, and immunofluorescence labelling found and recovered the aberrant area. HUCM-derived stem cells and spermidine-derived exosomes biophysically match. These traits strengthen and prolong endometrial function. Pregnant rats with HUCMSC and SN had thinner endometrium. Hydrogel-incorporated HEHUCMSC and SN exosomes may improve IUI in rats with thin endometrium.

Chinese guidelines on the management of endometrial hyperplasia

• Endometrial hyperplasia can be classified as either hyperplasia without atypia or atypical hyperplasia. • Abnormal uterine bleeding is the most common symptom of endometrial hyperplasia. Transvaginal ultrasound is recommended for initial imaging to evaluate endometrial hyperplasia (evidence level 2+), while transrectal ultrasound is recommended for virgo patients (evidence level 3). • Endometrial biopsy should be used to confirm diagnosis in patients where endometrial lesions are suspected. Effective histological approaches to make definite diagnoses include diagnostic curettage (evidence level 2++), hysteroscopic-guided biopsy (evidence level 2+) and endometrial aspiration biopsy (evidence level 2-). • Progesterone is the preferred medication for the treatment of endometrial hyperplasia without atypia. Compared to oral progestins, placement of a levonorgestrel-releasing intrauterine system (LNG-IUS) has been associated with higher regression rates, lower recurrence rates and fewer adverse events which can be the initial treatment method. (Meta evidence level 1-, RCT evidence level 2+). Ultrasound and endometrial biopsies should be performed every 6 months during treatment to evaluate its effect and treatment should continue until no pathological changes are observed in two consecutive endometrial biopsies. Hysterectomy is not the preferred choice of treatment for patients with endometrial hyperplasia without atypia. • Minimally invasive hysterectomy is indicated for patients with endometrial atypical hyperplasia (evidence level 1+), bilateral fallopian tubes should also be removed (evidence level 2+). In cases where surgery cannot be tolerated, fertility is desired or the patient is younger than 45 years old, medical therapy is recommended (evidence level 3). LNG-IUS is the preferred medical therapy method (evidence level 2+). Endometrial pathologic evaluation should be performed every 3 months during conservative treatments, with adjustments made to dosages or approaches based on observed response to medication. Treatment should continue until no pathological changes are detected in two consecutive endometrial biopsies (evidence level 2++). There is no indication of sentinel lymph nodes biopsy and/or lymphadenectomy for hyperplasia with or without atypia. • Total hysterectomy is recommended to treat patients with recurrent endometrial atypical hyperplasia (evidence level 3); however, medical conservative therapy may be considered for patients hoping to become pregnant in the future. • Patients with fully regressed disease who would like to become pregnant should be advised to seek assistance through assisted reproductive technologies (evidence level 3). • Long-term follow-up is suggested for patients after endometrial hyperplasia treatment (evidence level 2+). Patient education is imperative for improving medication adherence, increasing regression rates and lowering recurrence rates (evidence level 3).

Intrauterine chilled saline instillation reduces endometrial impairment on MRI after ultrasound-guided percutaneous microwave ablation of uterine adenomyosis

OBJECTIVE

To investigate whether intrauterine chilled saline can reduce endometrial impairment during US-guided percutaneous microwave ablation (PMWA) of adenomyosis.

METHODS

An open-label, randomized trial was conducted with sixty symptomatic adenomyosis patients who were randomly assigned (1:1) to receive PMWA treatment assisted by intrauterine saline instillation (study group) or traditional PMWA treatment alone (control group). The primary endpoint was endometrial perfusion impairment grade on post-ablation contrast-enhanced MRI. The secondary endpoints were endometrial dehydration grade, ablation rate, and intra-ablation discomfort.

RESULTS

The baseline characteristics of the two groups were similar. The incidence rates of endometrial perfusion impairment on MRI in the study and control groups were 6.7% (2/30) and 46.7% (14/30), respectively (p < 0.001). There were 28 (93.3%), 2 (6.7%), 0, and 0 patients in the study group and 16 (53.3%), 7 (23.3%), 5 (16.7%), and 2 (6.7%) in the control group (p < 0.001) who had grade 0, 1, 2, and 3 perfusion impairment, respectively. Additionally, there were 27 (90%), 3 (10%), and 0 patients in the study group and 19 (63.3%), 10 (33.3%), and 1 (3.3%) in the control group who had grade 0, 1, and 2 endometrial dehydration (p = 0.01). The ablation rates achieved in the study and control groups were 93.3 ± 17% (range: 69.2-139.6%) and 99.7 ± 15.7% (range: 71.5-129.8%), and they were not significantly different (p = 0.14). No significant difference was found in the intra-ablation discomfort.

CONCLUSION

Intrauterine chilled saline can effectively reduce endometrial impairment after PMWA treatment for adenomyosis.

CRITICAL RELEVANCE STATEMENT

This trial demonstrated that the instillation of intrauterine chilled saline reduced endometrial impairment on MRI during PMWA of adenomyosis. This approach allows more precise and safe ablation in clinical practice.

KEY POINTS

Endometrial impairment occurs in the PMWA treatment of adenomyosis. Intrauterine chilled saline can reduce endometrial impairment during PMWA for adenomyosis. An intrauterine catheter is a practical endometrial protecting method during thermal ablation.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100053582. Registered 24 November 2021, www.chictr.org.cn/showproj.html?proj=141090 .

The volumetric ADC histogram analysis in differentiating stage IA endometrial carcinoma from endometrial polyp

OBJECTIVE

This study aimed to explore the value of apparent diffusion coefficient (ADC) histogram based on whole lesion volume in distinguishing stage IA endometrial carcinoma from the endometrial polyp.

METHODS

MRI of 108 patients with endometrial lesions confirmed by pathology were retrospectively analysed, including 65 cases of stage IA endometrial carcinoma and 43 cases of endometrial polyp. The volumetric ADC histogram metrics and general imaging features were evaluated and measured simultaneously. All the features were compared between the 2 groups. The receiver operating characteristic curve was utilized to evaluate the diagnostic performance.

RESULTS

The mean, max, min, and percentiles (10th, 25th, 50th, 75th, 95th) ADC values of endometrial carcinoma were significantly lower than that of polyp (all P < .05). The skewness and kurtosis of ADC values in the endometrial carcinoma group were significantly higher than those in the endometrial polyp group, and the variance of ADC values in the endometrial carcinoma group was lower than those in the endometrial polyp group (all P < .05). Endometrial carcinoma demonstrated more obvious myometrial invasion combined with intralesion haemorrhage than polyp (all P < .05). The 25th percentile of ADC values achieved the largest areas under the curve (0.861) among all the ADC histogram metrics and general imaging features, and the sensitivity and specificity were 83.08% and 76.74%, with the cut-off value of 1.01 × 10-3 mm2/s.

CONCLUSION

The volumetric ADC histogram analysis was an effective method in differentiating endometrial carcinoma from an endometrial polyp. The 25th percentile of ADC values has satisfactory performance for detecting malignancy in the endometrium.

ADVANCES IN KNOWLEDGE

The ADC histogram metric based on whole lesion is a promising imaging-maker in differentiating endometrial benign and malignant lesions.

Segment anything with inception module for automated segmentation of endometrium in ultrasound images

PURPOSE

Accurate segmentation of the endometrium in ultrasound images is essential for gynecological diagnostics and treatment planning. Manual segmentation methods are time-consuming and subjective, prompting the exploration of automated solutions. We introduce "segment anything with inception module" (SAIM), a specialized adaptation of the segment anything model, tailored specifically for the segmentation of endometrium structures in ultrasound images.

APPROACH

SAIM incorporates enhancements to the image encoder structure and integrates point prompts to guide the segmentation process. We utilized ultrasound images from patients undergoing hysteroscopic surgery in the gynecological department to train and evaluate the model.

RESULTS

Our study demonstrates SAIM's superior segmentation performance through quantitative and qualitative evaluations, surpassing existing automated methods. SAIM achieves a dice similarity coefficient of 76.31% and an intersection over union score of 63.71%, outperforming traditional task-specific deep learning models and other SAM-based foundation models.

CONCLUSIONS

The proposed SAIM achieves high segmentation accuracy, providing high diagnostic precision and efficiency. Furthermore, it is potentially an efficient tool for junior medical professionals in education and diagnosis.

The Utility of Pelvic Ultrasounds in Adolescents Presenting to the Emergency Department with Abnormal Uterine Bleeding

STUDY OBJECTIVE

To analyze what factors influence a provider's decision to order a pelvic ultrasound (PUS) in the emergency department (ED) for adolescents with abnormal uterine bleeding (AUB), to determine if endometrial stripe (EMS) measurements are used in treatment decisions, and to evaluate if treatment outcomes differ based on EMS thicknesses.

METHODS

Retrospective chart review of patients aged 11-19 presenting to the ED with AUB from 2006 to 2018. Those receiving a PUS were divided into three EMS groups: ≤5 mm, 6-9 mm, and ≥10 mm. Outcomes were evaluated in admitted patients by progress notes indicating resolution of bleeding. Cross-tab, χ2, and logistic and linear regression analysis were performed.

RESULTS

Of 258 adolescents meeting study criteria, 113 (43.8%) had a PUS. None had an abnormality. A PUS was more likely to be performed in patients with lower hemoglobin values (P < .003). Provider decision to order a PUS did not differ by age or bleeding duration (P > .1). Among those with a PUS, 67 (59%) received hormonal therapy (pill, progestin-only, IV estrogen). There were no significant differences in treatment choices based on EMS (P < .061) or, among the 44 admitted patients (17%), in the time it took bleeding to stop after initiating treatment (pill: P = .227, progestin-only: P = .211, IV estrogen: P = .229).

CONCLUSION

In adolescents with AUB in the ED, performing a PUS was more common in those with low hemoglobin. EMS thickness did not appear to affect treatment decisions or inpatient outcomes. Larger studies are needed to confirm the current findings and determine if PUS is needed in the evaluation of AUB.

Effect of changes in the menstrual cycle and age on the signal intensity of amide proton transfer imaging in the normal uterus: a preliminary study

PURPOSE

To analyze the effect of changes in the menstrual cycle and age on the signal intensity of amide proton transfer (APT) imaging in normal uterine structures.

METHODS

Thirty-one healthy females (age: 21-50 years old) underwent regular pelvic MRI and APT sequences during their menstrual cycle. The APT values of the endometrium, myometrium, and junctional zone were measured. One-way and multi-way analyses of variance were used to analyze the data. Intraindividual difference and Pearson's correlation analyses were also conducted.

RESULTS

The APT values of the uterine structures during the menstrual, proliferative, and secretory phases were 3.413 ± 0.682%, 4.776 ± 0.829%, and 5.218 ± 0.772% for the endometrium; 2.966 ± 0.533%, 3.597 ± 0.380%, and 4.324 ± 0.583% for the myometrium; and 1.703 ± 0.393%, 2.362 ± 0.486%, and 2.779 ± 0.528% for the junctional zone. The individual variation in the APT values of the normal uterus during the three menstrual phases was 1.1-1.7%.There were no significant differences in APT values of uterine structures with age. The APT values of the endometrium were greater than those of other structures (P < 0.05).The Pearson correlation coefficients between APT values of uterine structures and menstrual cycle were 0.686, 0.743, and 0.684, respectively.

CONCLUSION

The menstrual cycle had a significant effect on the APT signal intensities of the uterine structures, whereas premenopausal age had no significant effect. Changes in the uterine structures during the menstrual cycle should be considered when using APT to diagnose suspected uterine lesions.

The newly non-uniform endometrial echogenicity on transvaginal ultrasound do not impact in vitro fertilization and embryo transfer success: A retrospective cohort study

OBJECTIVE

To evaluate the effect of newly non-uniform endometrial echogenicity diagnosed by transvaginal ultrasound on the outcome of pregnancy in vitro fertilization-embryo transfer (IVF-ET) during controlled ovarian hyperstimulation (COH) by retrospective cohort analysis.

METHODS

A retrospective cohort study of a total of 604 patients with newly non-uniform endometrial echogenicity from January 2013 to June 2017, each woman was matched with three control subjects of similar age (±1 year), type of infertility (primary or secondary), the protocol used for COH, and the number of ET cycles in our unit. The patients in the study group and control group were matched according to the strict 1:3 matching principle. Baseline characteristics and pregnancy outcomes were compared.

RESULTS

There were no statistically significant difference in baseline characteristics, live birth rate, biochemical pregnancy rate, clinical pregnancy rate, clinical pregnancy miscarriage rate and ectopic pregnancy rate between the two groups. But there were significant statistical differences in past history of uterine cavity surgery between the two groups (35.26% VS 21.19%), especially in history of endometrial polyp surgery (94.84% VS 90.10%).

CONCLUSIONS

Our results demonstrate the newly diagnosed non-uniform endometrial echogenicity during controlled ovarian hyperstimulation does not affect the pregnancy outcome of in vitro fertilization-embryo transfer, and fresh embryo transfer can be continued.

Transplantation of umbilical cord-derived mesenchymal stem cells promotes the recovery of thin endometrium in rats

The endometrium plays a critical role in embryo implantation and pregnancy, and a thin uterus is recognized as a key factor in embryo implantation failure. Umbilical cord mesenchymal stem cells (UC-MSCs) have attracted interest for the repair of intrauterine adhesions. The current study investigated the repair of thin endometrium in rats using the UC-MSCs and the mechanisms involved. Rats were injected with 95% ethanol to establish a model of thin endometrium. The rats were randomly divided into normal, sham, model, and UC-MSCs groups. Endometrial morphological alterations were observed by hematoxylin-eosin staining and Masson staining, and functional restoration was assessed by testing embryo implantation. The interaction between UC-MSCs and rat endometrial stromal cells (ESCs) was evaluated using a transwell 3D model and immunocytochemistry. Microarray mRNA and miRNA platforms were used for miRNA-mRNA expression profiling. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses were performed to identify the biological processes, molecular functions, cellular components, and pathways of endometrial injury and UC-MSCs transplantation repair and real-time quantitative reverse transcription PCR (qRT-PCR) was performed to further identify the expression changes of key molecules in the pathways. Endometrium thickness, number of glands, and the embryo implantation numbers were improved, and the degree of fibrosis was significantly alleviated by UC-MSCs treatment in the rat model of thin endometrium. In vitro cell experiments showed that UC-MSCs migrated to injured ESCs and enhanced their proliferation. miRNA microarray chip results showed that expression of 45 miRNAs was downregulated in the injured endometrium and upregulated after UC-MSCs transplantation. Likewise, expression of 39 miRNAs was upregulated in the injured endometrium and downregulated after UC-MSCs transplantation. The miRNA-mRNA interactions showed the changes in the miRNA and mRNA network during the processes of endometrial injury and repair. GO and KEGG analyses showed that the process of endometrial injury was mainly attributed to the decomposition of the extracellular matrix (ECM), protein degradation and absorption, and accompanying inflammation. The process of UC-MSCs transplantation and repair were accompanied by the reconstruction of the ECM, regulation of chemokines and inflammation, and cell proliferation and apoptosis. The key molecules involved in ECM-receptor interaction pathways were further verified by qRT-PCR. Itga1 and Thbs expression decreased in the model group and increased by UC-MSCs transplantation, while Laminin and Collagen expression increased in both the model group and MSCs group, with greater expression observed in the latter. This study showed that UC-MSCs transplantation could promote recovery of thin endometrial morphology and function. Furthermore, it revealed the expression changes of miRNA and mRNA after endometrial injury and UC-MSCs transplantation repair processed, and signaling pathways that may be involved in endometrial injury and repair.

Does a hyperechogenic endometrial mass in the uterus during controlled ovarian stimulation affect assisted reproductive technology cycle outcomes?

OBJECTIVES

Healthy embryos and endometrial receptivity are keys to the success of in-vitro fertilization and embryo transfer (IVF-ET). Abnormal transvaginal ultrasonography (TVU) findings in the endometrium are a concern during assisted reproductive technology (ART) treatments. Observation of a hyperechogenic endometrial mass (HEM) during controlled ovarian stimulation (COS) in an IVF or intracytoplasmic sperm injection (ICSI) cycle is a dilemma. Here we investigated whether an HEM would affect ART cycle outcomes.

STUDY DESIGN

We analyzed all data from patients who underwent IVF or ICSI treatment cycles from January 1, 2009 to December 31, 2016 at our institution. Patients diagnosed with an HEM were included. Each woman was matched with two control subjects of similar age (± 1 year), in terms of the number of cycles, type of infertility (primary or secondary), protocol used for COS, but with no HEM identified by TVU. Baseline characteristics, COS response, and pregnancy outcomes after ET were compared.

RESULTS

In all, 1088 patients were diagnosed with an HEM. Of these, 426 met the inclusion criteria and were matched with 852 controls. Baseline characteristics showed no significant differences between the groups. The peak endometrial thickness was significantly greater in the experimental group than in the control group (1.15 ± 0.18 cm vs. 1.08 ± 0.21 cm, p < 0.001). The live birth rates were 43.7% vs 46.2% in the experimental and control groups, respectively. There were no significant between-group differences in the rates of biochemical or clinical pregnancy or abortions at any stage.

CONCLUSIONS

Newly diagnosed HEMs < 18 mm in diameter monitored by TVU did not impair the outcomes of ART following COS in this study. If other conditions are suitable, completion of ART cycles should be the appropriate approach in such cases.

KEY MESSAGE

Newly diagnosed hyperechogenic endometrial masses measuring <18 mm in diameter monitored by TVU during COS did not adversely affect the outcomes of these IVF/ICSI-ET cycles.

Endometrium imaging using real-time rotational optical coherence tomography imaging system: A pilot, prospective and ex-vivo study

This study aimed to evaluate a novel real-time rotational optical coherence tomography (OCT) imaging system (OCTIS) with a fiber-optic probe to look at endometrium and to correlate the OCTIS images with standard histology. OCT could obtain real-time images resembling histological examination. With recent development of customized probes, it allows OCT to be used in the field of gynecology.This is a pilot, prospective, ex-vivo and observational study. Women underwent hysterectomy for various gynecological conditions were recruited and OCTIS images were obtained from endometrium of 15 fresh uterus specimens immediately after hysterectomy. The excised uterus was cut open and OCTIS imaging was obtained. The scanned region of endometrium was excised for histological examination and OCTIS images were precisely compared to corresponding histological images and ultrasound images. Blinded qualitative analysis on OCTIS images was performed by 2 assessors to determine inter-rating reliability on the histopathological diagnosis.Epithelium, glands, cysts, and stroma of endometrium were clearly seen by the OCTIS. Different phases of menstrual cycle of normal endometrium could be differentiated and pathological condition such as hyperplastic and dysplasic endometrium, which corresponded well with histological findings, could be identified. The inter-rater reliability between assessors on overall OCTIS endometrium and neoplastic OCTIS endometrium was moderate (Kendall τb of 0.58) and substantial (Kendall τb of 0.76), respectively.OCTIS can provide real-time, high-resolution and rotational imaging modality to view endometrial structure with high consistency with histological examination and satisfactory agreement between observers. It has a great potential to be developed in the clinical use of endometrial assessment for gynecological applications.

More Than Just 2 Layers: A Comprehensive Multimodality Imaging Review of Endometrial Abnormalities

Endometrial abnormalities develop in female patients of all ages. Symptoms related to endometrial pathologies are among the most common causes of gynecologist office visits, with the radiologists playing an important role in endometrial evaluation. In some instances, the radiologist may be the first physician to note endometrial pathology. In this article, we will provide a comprehensive review of radiologic modalities utilized in the evaluation of the endometrium, as well as the imaging appearance of various endometrial disease processes.