Feasibility of EUS-guided shear-wave measurement: A preliminary clinical study

The Role of Endoscopic Ultrasound and Ancillary Techniques in the Diagnosis of Autoimmune Pancreatitis: A Comprehensive Review

Autoimmune pancreatitis (AIP) is a unique form of chronic pancreatitis with a multifactorial pathogenesis. Historically, it has been classified as type 1 and type 2, according to its clinical and histological features. The diagnosis of AIP is challenging and relies on a combination of clinical, histopathologic, serologic, and imaging characteristics. In the available guidelines, the imaging hallmarks of AIP are based on cross-sectional imaging and cholangiopancreatography retrograde endoscopic findings. Endoscopic ultrasound (EUS) is generally used for pancreatic tissue acquisition to rule out pancreatic cancer and diagnose AIP with limited accuracy. Several papers reported the reliability of EUS for providing informative morphologic features of AIP. Nowadays, the improvement in the resolution of EUS conventional images and the development of new ancillary technologies have further increased the diagnostic yield of EUS: contrast-enhanced EUS and EUS elastography are non-invasive and real-time techniques that strongly support the diagnosis and management of pancreatic diseases. In this review article, we will present the role of conventional EUS and ancillary diagnostic techniques in the diagnosis of AIP to support clinicians and endosonographers in managing this condition.

Endoscopic Ultrasound-based Shear Wave Elastography for Detection of Advanced Liver Disease

BACKGROUND AND AIMS

Endoscopic ultrasound shear wave elastography (EUS-SWE) is a novel modality for liver stiffness measurement. The aims of this study are to evaluate the performance and reliability of EUS-SWE for detecting advanced liver disease in a prospective cohort.

METHODS

EUS-SWE measurements were prospectively obtained from patients undergoing EUS between August 2020 and March 2023. Liver stiffness measurements were compared between patients with and without advanced liver disease (ALD), defined as stage ≥3, to determine diagnostic accuracy for advanced fibrosis and portal hypertension. Logistic regression was performed to identify variables that impact the reliability of EUS-SWE readings. Select patients underwent paired magnetic resonance elastography (MRE) for liver fibrosis correlation.

RESULTS

Patients with ALD demonstrated higher liver stiffness compared to healthy controls (left lobe: 17.6 vs. 12.7 kPa, P<0.001; median right lobe: 24.8 vs. 11.0 kPa, P<0.001). The area under the receiver operator characteristic (AUROC) for the detection of ALD was 0.73 and 0.80 for left and right lobe measurements, respectively. General anesthesia was associated with reliable EUS-SWE liver readings (odds ratio: 2.73, 95% CI: 1.07-7.39, P=0.040). Left lobe measurements correlated significantly with MRE with an increase of 0.11 kPa (95% CI: 0.05-0.17 kPA) for every 1 kPa increase on EUS-SWE. D.

CONCLUSIONS

SWE is a promising technology that can readily be incorporated into standard EUS examinations for the assessment of ALD.

Endoscopic Ultrasound (EUS) Guided Elastography

Endoscopic ultrasound (EUS) is an essential technique for the management of several diseases. Over the years, new technologies have been developed to improve and overcome certain limitations related to EUS-guided tissue acquisition. Among these new methods, EUS-guided elastography, which is a real-time method for the evaluation of tissue stiffness, has arisen as one of the most widely recognized and available. At present, there are available two different systems to perform an elastographic evaluation: strain elastography and shear wave elastography. Strain elastography is based on the knowledge that certain diseases lead to a change in tissue hardness while shear wave elastography monitored shear-wave propagation and measures its velocity. EUS-guided elastography has shown in several studies high accuracy in differentiating benign from malignant lesions from many different locations, mostly in the pancreas and lymph nodes. Therefore, nowadays, there are well-established indications for this technology, mainly for supporting the management of pancreatic diseases (diagnosis of chronic pancreatitis and differential diagnosis of solid pancreatic tumors) and characterization of different diseases. However, there are more data on new potential indications for the near future. In this review, we will present the theoretical bases of this technology and we will discuss the scientific evidence to support its use.

Diagnosing chronic pancreatitis by endoscopic ultrasound assessing the association between ultrasound and pathological findings: A narrative review

Endoscopic ultrasound (EUS) is widely recognized for its non‐invasiveness and for its usefulness in chronic pancreatitis (CP) diagnosis, including early CP. Although it is desirable to obtain a definitive diagnosis of CP by tissue sampling with EUS‐guided fine needle aspiration, histopathological changes in CP are heterogeneous in terms of the extent and the distribution of lesions. Therefore, histopathological diagnosis of appropriate tissue sampling by EUS‐fine needle aspiration is expected to be difficult. Furthermore, it is virtually impossible to match EUS images with pathological sections, making direct contrast between EUS findings and pathology difficult. This narrative review presents a discussion of the diagnosis of CP/early CP by EUS, particularly assessing the association between ultrasound and pathological findings. Recently, the histological corroboration and correlation of EUS findings related to CP have been clarified by surgical specimens, including those obtained from animal studies. Furthermore, remarkable advances have occurred in the objective and quantitative diagnosis of pancreatic fibrosis by EUS‐elastography. Future technological advances in EUS are expected to improve the accuracy of diagnosis of pancreatic fibrosis at earlier stages.

Current Status of the Diagnosis of Early-Stage Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) can be treated with surgery, chemotherapy, and radiotherapy. Despite medical progress in each field in recent years, it is still insufficient for managing PDAC, and at present, the only curative treatment is surgery. A typical pancreatic cancer is relatively easy to diagnose with imaging. However, it is often not recommended for surgical treatment at the time of diagnosis due to metastatic spread beyond the pancreas. Even if it is operable, it often recurs during postoperative follow-up. In the case of PDAC with a diameter of 10 mm or less, the 5-year survival rate is as good as 80% or more, and the best index for curative treatment is tumor size. The early detection of pancreatic cancer with a diameter of less than 10 mm or carcinoma in situ is critical. Here, we provide an overview of the current status of diagnostic imaging features and genetic tests for the accurate diagnosis of early-stage PDAC.

Endoscopic ultrasonography: Enhancing diagnostic accuracy

Endoscopic ultrasound (EUS) is an essential technique for the management of several diseases. Over the years, new technologies have been developed because to improve and overcome certain limitations related to EUS guided tissue acquisition. Among these new methods, EUS guided elastography and contrast enhanced EUS has arisen as the most widely recognized and available. We will review in this manuscript the different techniques of elastography and contrast enhancement. Nowadays, there are well establish indications for advance imaging, mainly for supporting the management of pancreatic diseases (diagnosis of chronic pancreatitis and differential diagnosis of solid and cystic pancreatic tumors) and characterization of lymph nodes. However, there are more data on new potential indications for the near future.

Advances in the imaging of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms comprise a heterogeneous group of tumors that differ in their pathogenesis, hormonal syndromes produced, biological behavior and consequently, in their requirement for and/or response to specific chemotherapeutic agents and molecular targeted therapies. Various imaging techniques are available for functional and morphological evaluation of these neoplasms and the selection of investigations performed in each patient should be customized to the clinical question. Also, with the increased availability of cross sectional imaging, these neoplasms are increasingly being detected incidentally in routine radiology practice. This article is a review of the various imaging modalities currently used in the evaluation of neuroendocrine neoplasms, along with a discussion of the role of advanced imaging techniques and a glimpse into the newer imaging horizons, mostly in the research stage.

Current status of the diagnosis of chronic pancreatitis by ultrasonographic elastography

Chronic pancreatitis (CP) is pathologically characterized by the loss of exocrine pancreatic parenchyma, irregular fibrosis, cellular infiltration, and ductal abnormalities. Diagnosing CP objectively is difficult because standard diagnostic criteria are insufficient. The change of parenchymal hardness is the key factor for the diagnosis and understanding of the severity of CP. The ultrasonography (US) or endoscopic ultrasonography (EUS) elastography have been used to diagnose pancreatic diseases. Both strain elastography (SE) and shear wave elastography are specific diagnostic techniques for measuring tissue hardness. Most previous studies were conducted with SE. There are three methods of interpreting SE; the method of recognizing the patterns in SE distribution images in the region of interest, the method of using strain ratio to compare the hardness of adipose tissue or connective tissue with that of the lesion, and the method of evaluating the hardness distribution of a target by histogram analysis. These former two methods have been used primarily for neoplastic diseases, and histograms analysis has been used to assess hardness distribution in the evaluation of CP. Since the hardness of the pancreas increases with aging, it is necessary to consider the age in the diagnosis of pancreatic disorders using US or EUS elastography.

Impact of endoscopic ultrasound elastography in pancreatic lesion evaluation

Pancreatic malignancy still becomes a major global problem and is considered as one of the most lethal cancers in the field of gastroenterology. Most patients come in the late stage of the disease due to organ’s location, and until now the treatment result is still far away from satisfaction. Early detection is still the main key for good, prolonged survival. However, discerning from other types of tumor sometimes is not easy. Endoscopic ultrasound (EUS) is still the best tool for pancreatic assessment, whereas fine-needle aspiration biopsy (FNAB) is considered as the cornerstone for further management of pancreatic malignancy. Several conditions have become a concern for EUS-FNAB procedure, such as risk of bleeding, pancreatitis, and even needle track-seeding. Recently, an artificial intelligence innovation, such as EUS elastography has been developed to improve diagnostic accuracy in pancreatic lesions evaluation. Studies have shown the promising results of EUS elastography in improving diagnostic accuracy, as well as discerning from other tumor types. However, more studies are still needed with further considerations, such as adequate operator training, expertise, availability, and its cost-effectiveness in comparison to other imaging options.

Recent Advances in Endosonography-Elastography: Literature Review

Ultrasonographic elastography is a modality used to visualize the elastic properties of tissues. Technological advances in ultrasound equipment have supported the evaluation of elastography (EG) in endosonography (EUS). Currently, the usefulness of not only EUS-strain elastography (EUS-SE) but also EUS-shear wave elastography (EUS-SWE) has been reported. We reviewed the literature on the usefulness of EUS-EG for various diseases such as chronic pancreatitis, pancreatic solid lesion, autoimmune pancreatitis, lymph node, and gastrointestinal and subepithelial lesions. The importance of this new diagnostic parameter, "tissue elasticity" in clinical practice might be applied not only to the diagnosis of liver fibrosis but also to the elucidation of the pathogeneses of various gastrointestinal diseases, including pancreatic diseases, and to the evaluation of therapeutic effects. The most important feature of EUS-EG is that it is a non-invasive modality. This is an advantage not found in EUS-guided fine needle aspiration (EUS-FNA), which has made remarkable progress in the field of diagnostics in recent years. Further development of artificial intelligence (AI) is expected to improve the diagnostic performance of EUS-EG. Future research on EUS-EG is anticipated.

Comprehensive review of diagnostic modalities for early chronic pancreatitis

Chronic pancreatitis (CP) is a progressive condition caused by several factors and characterised by pancreatic fibrosis and dysfunction. However, CP is difficult to diagnose at an early stage. Various advanced methods including endoscopic ultrasound based elastography and confocal laser endomicroscopy have been used to diagnose early CP, although no unified diagnostic standards have been established. In the past, the diagnosis was mainly based on imaging, and no comprehensive evaluations were performed. This review describes and compares the advantages and limitations of the traditional and latest diagnostic modalities and suggests guidelines for the standardisation of the methods used to diagnose early CP.

Cleansing efficacy and safety of bowel preparation protocol using sodium picosulfate/magnesium citrate considering subjective experiences: An observational study

BACKGROUND

Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.

AIM

To observe the intestinal cleansing efficacy and safety of sodium picosulfate/magnesium citrate and to discuss the patients’ experiences due to the procedure.

METHODS

Subjects hospitalized in the International Medical Center Ward of Peking University International Hospital, Beijing, China, from April 29 to October 29, 2020, for whom the colonoscopy was planned, were enrolled. Bowel preparation was performed using sodium picosulfate/magnesium citrate. The effect of bowel cleansing was evaluated according to the Ottawa Bowel Preparation Scale, defecation conditions and adverse reactions were recorded, and the comfort level and subjective satisfaction concerning medication were evaluated by the visual analogue scale/score (VAS).

RESULTS

The bowel preparation procedure was planned for all patients enrolled, which included 42 males and 22 females. The results showed an average liquid rehydration volume of 3000 mL, an average onset of action for the first dose at 89.04 min, an average number of bowel movements of 4.3 following the first dose, an average onset of action for the second dose at 38.90 min and an average number of bowel movements of 5.0 after the second dose. The total average Ottawa Bowel Preparation Scale score was 3.6, with 93.55% of bowel preparations in the “qualified” and 67.74% in the “excellent” grade. The average VAS score of effect on sleep was 0, and the average VAS score of perianal pain was also 0. The average VAS score for ease of taking and taste perception of the bowel cleanser was 10. Side effects included mild to moderate nausea (15.63%), mild vomiting (4.69%), mild to moderate abdominal pain (7.81%), mild to moderate abdominal distension (20.31%), mild palpitation (7.81%) and mild dizziness (4.69%).

CONCLUSION

Sodium picosulfate/magnesium citrate is effective and safe for bowel preparation before colonoscopy with high subjective patient acceptance, thus improving overall patient compliance.

Diagnostic performance of endoscopic ultrasonography-guided elastography for solid pancreatic lesions: Shear-wave measurements versus strain elastography with histogram analysis

BACKGROUND AND AIMS

Endoscopic ultrasound (EUS) elastography (EUS-EG) is a minimally invasive diagnostic method for evaluating tissue elasticity. The aim of this study was to evaluate the feasibility of newly developed EUS shear-wave measurement (EUS-SWM) and to compare diagnostic performance between EUS-SWM and the conventional strain elastography (SE) for the measurement of elasticity of solid pancreatic lesions (SPLs).

METHODS

From December 2017 until August 2019, we retrospectively reviewed 64 consecutive cases with SPLs who underwent both EUS-SWM and SE. EUS-SWM was used to measure the shear-wave velocity, Vs (m/s), and the unique measurement reliability index, VsN (%), in the target lesion. SE images were assessed by strain histogram (SH) analysis, and the mean strain value of the elasticity index was measured. We evaluated the diagnostic performance of EUS-SWM and SE with SH to characterize the SPLs.

RESULTS

The Vs (m/s) values of SPLs were 2.19 for pancreatic cancer (PC), 1.31 for pancreatic neuroendocrine neoplasm (PanNEN), 2.56 for mass-forming pancreatitis (MFP) and 1.58 for metastatic tumors. Vs showed no significant difference based on the disease. The mean strain values were 45.5 for PC, 47.3 for PanNEN, and 74.5 for MFP. In the comparison of tissue elasticity between PC and MFP, Vs showed no significant difference (P = 0.5687); however, the mean strain value was significantly lower in PC cases (45.4 vs 74.5: P = 0.0007).

CONCLUSION

Endoscopic ultrasound SWM tended to be unstable for the measurement of elasticity of SPLs, and conventional SE with SH was superior for their characterization.

The Role of Endoscopic Ultrasound in Pancreatic Cancer Staging in the Era of Neoadjuvant Therapy and Personalised Medicine

Precise staging of pancreatic cancer is crucial for treatment choice. In clinical practice, this includes the TNM staging and determination of tumour resectability, based on a multimodality imaging workup. International guidelines recommend multi-detector computed tomography (CT), with a dedicated pancreatic protocol, as the first-line tool for TNM staging and evaluation of tumour-vessel relationships. In non-metastatic disease upon initial CT assessment, both magnetic resonance imaging and endoscopic ultrasound (EUS) may add relevant information, potentially changing treatment sequence. EUS may have distinct advantages in pancreatic cancer diagnosis and staging when compared with other modalities, being particularly valuable in the determination of portal venous confluence involvement (particularly in small and ill-defined/isoattenuating tumours on CT), in locoregional nodal staging and in the detection of ascites. As we step forward to a more frequent use of neoadjuvant chemotherapy and to personalised medicine, the importance of EUS-guided fine-needle biopsy (EUS-FNB) also increases. The recent availability of third-generation biopsy needles significantly increased the diagnostic yield of EUS-guided tissue acquisition, providing diagnostic cell blocks in approximately 95% of cases with only two dedicated passes and allowing ancillary testing, such as immunohistochemistry and molecular profiling of the tumour. In this article, the authors present an updated perspective of the place of EUS and EUS-FNB in the staging algorithm of pancreatic cancer. Data supporting the increasing role of neoadjuvant therapy and the importance of a patient-tailored treatment selection, based on tumoural subtyping and molecular profiling, are also discussed.

Do we need elastography for EUS?

We recently introduced a series of papers “What should be known prior to performing EUS exams.” In Part I, the authors discussed which clinical information and whether other imaging modalities are needed before embarking EUS examinations. In Part II, technical controversies on how EUS is performed were discussed from different points of view. In this article, important practical issues regarding EUS elastography will be raised and controversially discussed from very different points of view.